Plant Science Bulletin archive
Issue: 1965 v11 No 3 Fall
PLANT SCIENCE BULLETIN
A Publication of the Botanical Society of America, Inc.
VOLUME 11 DECEMBER, 1965 NUMBER 3
The Next New Biology1
In the olden days, up to two or three years ago, I gave talks with titles like "The New Biology," and this was a good subject to talk about because, as we all know, there has been a whole new biology—the new cell biology—appear before our eyes during the 1950's and the early 1960's. But, biology keeps developing; it's evidently in log phase, with a knowledge doubling time of something like two years, and during the last two or three years I have been giving talks with titles like "The New, New Biology." We can, however, already foresee the end of the new, new biology. What will be left? With what will we concern ourselves after the new, new biology has been so fully exploited that what is left is not so interesting to find out? With what will the next new biology be concerned? It is well to be prepared in matters of this kind so that we can know ahead how to prepare ourselves for the challenges of the future. Let us think about the next new biology. Just to be sure that we are all thinking within the same general framework, I will first talk a little bit about the old, new biology, and then go on to the new, new biology—its content, its current frontiers, and its ultimate shape as it approaches perfection. We will then go on to consider candidates for the next new biology.
The old new biology has been concerned with the molecular facts of cell life, with finding out what it is that makes a cell be alive. We now know that all cells contain the directions for cell life written in the DNA of their chromosomes, and that these directions include specification of how to make the many kinds of protein enzyme molecules by means of which the cell converts available building blocks into sub-stances suitable for making more cells. We know that to make enzyme molecules the DNA prints off RNA copies of itself, messenger RNA molecules, and that these messenger RNA molecules are decoded by ribosomes, also made by the DNA, and that the ribosome as it decodes a messenger RNA molecule uses the information to assemble a specific kind of enzyme molecule. This picture of life is that given to us by molecular biology, and it is general, it applies to all cells of all creatures. The old new biology is as simple as
1 Address of the President of the Pacific Division, American Association for the Advancement of Science; presented June 22, 1965 at Riverside, California. that—the DNA makes the RNA makes the enzymes—the enzymes make the building blocks for making more enzymes, more RNA, and all of this so that some enzymes can be concerned with making building blocks with which the DNA may replicate itself, so that the DNA can double, so that the cell can divide into two, so that that kind of cell can multiply and multiply and take over the world, as for example human cells are now doing.
In lower organisms, which consist of single cells, every cell is alike. A higher creature consists, however, of many different kinds of specialized cells. Each of us arises from a single cell, the fertilized egg, which divides and divides and pretty soon the individual cells begin to be different from one another—to give rise to xylem or phloem, or muscle or nerve, to produce the particular kinds of cells that are required to produce an adult creature. This is development and differentiation, and it is with this subject, viewed through the window of the new biology, that the new, new biology is concerned.
The first thing that we can say about development viewed through the eyes of the molecular biologist is that all the cells of the body of a higher organism have exactly the same amount and kind of DNA—the same genetic information. That this is so is evident not only from the constancy in amount of DNA per cell in higher creatures, but also, in the case of plants, from the fact that many different individual kinds of specialized cells can be separated from the adult body, put into appropriate nutrient medium, and caused to regenerate the whole organism—grow through the whole life cycle. Quite evidently each mature specialized cell contains the entire genetic information of the organism. Nonetheless, as we know, some cells produce hemoglobin, others do not. Some produce muscle enzymes, some Iiver enzymes, and so on. The genetic information for making hemoglobin, for example, is in all cells of the body, but is used in only a few cells, those which are to be red blood cells. In other cells of the body, the genetic information for making hemoglobin is turned off—repressed. To find out what it is that causes development and differentiation, then, we must find out what it is in the cell that determines that particular units of the genetic information, particular genes, shall be active and make their characteristic messenger RNA, and what it is that
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determines that other genes shall be repressed, inactive in messenger RNA-making.
Development is the orderly production by a single cell, the fertilized egg, of the several kinds of specialized cells which make up the adult creature. Specialized cells differ from one another in the kinds of enzymes which they contain. We are inexorably led by logic to the conclusion that the cause of development is a properly programmed expression and utilization of the genetic information. The genetic in-formation is contained in the genes, and these in turn are fastened together into the chromosomes which are housed in the cell nucleus. The new, new biology, the study of development, must therefore be occupied with the study of chromosomes, since it is in the chromosomes that the master plan for the architecture of the body resides. My associate, Professor Ru-chih C. Huang, and I have started such a study. During the past five years we have found out how to isolate chromosomes, and how to cause them to make their messenger RNA in the test tube. We have studied the control and programming of genetic activity on three levels, namely (1) the hardware of genetic control, the nature of the material which represses gene activity; (2) the nature of the genetic switching unit, the nature of the act by which genetic activity is turned on and off, and (3) the nature of the switching network, of the program by means of which the individual genetic switching units are linked and integrated into a developmental system.
Firstly, then, we have had to isolate chromosomes—the genetic material. This has turned out to be ridiculously easy—we just grind up some tissue, filter off the cell membranes, and centrifuge it in a centrifugal field which is just insufficient to pellet the mitochondria. Only the largest and heaviest things in the cell grindate sediment. Luckily, the heaviest and densest things in the grindate are the chromosomes, and they pellet in a centrifugal field of 4,000 x g. The crude chromosomes may be purified by sucrose density gradient centrifugation to yield in high purity, and with a high recovery, the genetic material of the original tissue. This method of isolation of chromosomes is a general one. We have applied it first to the pea plant. We say, if pea plants were good enough for Mendel to invent genetics with, they are good enough for us. But the methods which we have used for pea plants have turned out to be applicable to the tissues of cows, rats, humans, insects, and even bacteria.
Chromosomes isolated according to the procedures out-lined above possess a not uninteresting property, namely, they are able to catalyze the synthesis of messenger RNA from the four riboside triphosphates. That chromosomes possess this power is due in the first place to the fact that they contain bound in their structure the enzyme RNA polymerase, which catalyzes the union of the ribonucleotides to one another, provided only that a DNA template is avail-able. The chromosome of course provides the DNA template. We have found further that RNA synthesis by isolated chromosomes is limited in its rate by the amount of RNA polymerase contained in the chromosome. That this is so is shown by the fact that if purified RNA polymerase (isolated for example from the bacterium E. cols) is added to a chromosomal preparation in the presence of the four riboside triphosphates, rate of RNA synthesis is enormously increased, 100, 200 or several hundred-fold over that caused by the endogenous enzyme alone. We have, therefore, a means at our disposal for assessing the template activity of chromosomal RNA, for determining the amount of DNA in the chromosome which is capable of acting as template for the production of messenger RNA by DNA-dependent RNA synthesis.
The DNA of chromosomes is less effective in the support of DNA-dependent RNA synthesis by RNA polymerase than is an equal amount of pure, deproteinized DNA. This is because the DNA of the chromosome is present in two forms. The first form, a minority form which makes up only some 5-20% of the chromosomal DNA, behaves like DNA. It supports RNA synthesis by RNA polymerase and possesses some of the physical and chemical properities of DNA. The remainder of the chromosomal DNA, some 80-95 % or more, is not capable of supporting DNA-dependent RNA synthesis by RNA polymerase. This is because this portion of the chromosomal DNA is complexed with a special and unique chromosomal component, proteins of a class known as his-tones. The histones are positively charged proteins which bind to and specifically complex with DNA, covering the DNA surface and making it inaccessible to RNA polymerase. We have developed methods for the physical separation from one another of the DNA which is completely complexed with histone, the nucleohistone component of chromosomes, from the DNA not so-complexed with histone. By such fractionation methods it has been possible to show that genes which are repressed in life are present in the histone-covered portion of the chromosomes, while genes which in life are not repressed, are present in the histone-free portion of the genetic material. Analysis of these matters has been made
easier in our hands by the attention which we have focused upon a particular gene of the pea plant. This is a gene which supports the making of messenger RNA which in turn supports the making of the reserve protein of pea seed cotyledons. This protein, pea seed globulin, is made only during the growth of the pea seed, and is deposited therein. The gene is repressed, pea seed globulin is not made, in any other part of the pea plant at any other time in the life cycle of the pea plant. We have shown, for example, that chromosomes from developing pea cotyledons produce messenger RNA, in the test tube, which supports in turn the making of protein by a purified ribosomal preparation. The protein thus synthesized contains pea seed globulin, and in approximately the same proportion of total protein as is found in the developing pea seed itself. Chromosomes from, for ex-ample, vegetative pea buds, also support the making of messenger RNA which also supports the synthesis of protein by a ribosomal protein-making system. The protein synthesized under the supervision of pea bud chromosomes contains no detectable amount of pea seed globulin, however. We have shown that the gene for pea seed globulin-making is present in the histone-poor portion of the DNA of pea cotyledon chromatin. We have further found that the gene for pea seed globulin-making may be derepressed in pea bud chromatin by removal of the histones from the pea bud chromatin DNA.
So, therefore, the histones are repressors. So far as we have been able to discover, all repressors of genetic activity in the chromosomes of higher creatures are histones. The histones are made in the nucleus, apparently in the nucleolus, and are deposited on the DNA at the time of DNA replication. How does a histone molecule find the right gene to sit on, and repress? The interaction of histone with DNA is, as remarked above, a purely ionic one. When we in the Iaboratory wish to dissociate histone from DNA, we merely put the chromosome into a solution of high salt concentration, in which ionic interactions are greatly diminished in effectiveness. Neither we, nor anybody else, has been able to find any specificity in the interaction between histone and DNA, that is, histone does not seek out and bind with a DNA molecule according to the information content of that DNA molecule. A histone cannot apparently read the genetic message contained in a DNA molecule; it merely notices that DNA is a negatively charged macromolecule. During recent months Professor Huang and I have come upon a new finding which we believe may illuminate the question of how the repressor molecules find the right gene upon which to sit. We have found that in the native chromosome each histone molecule has bound to it an RNA molecule. The histone-RNA linkage is cleaved by acid solutions, and since extraction of histones with acid is always used by histone chemists in the preparation of their materials, the fact that native histone contains bound RNA has thus far escaped notice. The RNA which is bound in the chromosomal structure is of an entirely new category, different from messenger RNA, transfer RNA, ribosomal RNA, in base composition, in size, and no doubt in function. In the chromosome, the histone-bound RNA is complexed to the DNA. In the world of the nucleic acids, "It takes one to know one." Perhaps it is this RNA which discovers the proper nucleotide sequence, the proper gene for the histone to complex to and which to repress.
Let us turn now to the question of how in nature genes get turned off and on. When we derepress genes in the laboratory by removal of histone, we do so by disassociating DNA from histone by the use of high concentrations of salt, as pointed out above. It works nicely, but not selectively. It derepresses all repressed genes. In the living cell derepression is selective, one or a few genes may be turned on or off without influencing others. We are, however, beginning to know something about the nature of this genetic switching unit. Just as in bacteria, so also in higher organ-isms, it has been found that there are particular kinds of small molecules which are able to turn off or on the activity of particular genes. In the bacterium, these are small molecules and genes concerned with the making of enzymes for the making of everyday metabolites, and the control serves the end of seeing to it that the bacterium does not make some particular kind of substance if that substance is available in the nutrient medium. In higher creatures this kind of regulation by small molecules serves the process of development, and one important class of such small molecules consists of the hormones. A hormone, on arrival at its target organ, turns on individual or whole sets of genes, causing the production of characteristic enzyme molecules, and setting a cell or cells on a new pathway of development. This is dramatically exemplified by the case of cortisone. Cortisone is produced in the adrenal cortex, and goes from the site of its production to the liver, for example. In the liver the cortisone says to the liver cell, "Please, cells of the liver, make me the following 12 enzymes." Cortisone causes derepression of genes previously repressed, or largely repressed, for the making of messenger RNA which supports the making of a whole array of particular kinds of enzyme molecules. It has been shown by physiologists who have worked upon the matter that cortisone, when it arrives in the liver, causes the liver cells to increase their rate of RNA synthesis, this RNA in turn supporting an increased rate of protein synthesis, the new protein consisting then of the new kinds of enzymes which are being produced. That cortisone acts by causing derepression of genes has been shown clearly and elegantly by our colleague Michael Dahmus. Mr. Dahmus has given cortisone to adrenalectomized rats and, after an appropriate period—three hours—isolated chromosomes from the liver of such treated rats, together with chromosomes from cortisone-not-treated rats. The chromosomes thus isolated have been incubated with excess of purified RNA polymerase as well as the four riboside triphosphates for estimate of the template activity for RNA synthesis of the two kinds of chromosomes. He has shown that the template activity of liver chromosomes is increased by approximately 30% by cortisone treatment in life. This is as one would expect. Cortisone appears, then, to remove the repressor substances from genes previously repressed.
In the case of cortisone, the template activity of the
chromatin is increased by 30%. Would it not be nice to find a case in which a hormone causes a dramatic increase in template activity of chromosomes? Such a case has been, in fact, found and studied by our colleague Dorothy Tuan. The buds of freshly harvested potatoes do not grow. They are said to be dormant. The chromosomes of the cells of the dormant bud are almost completely repressed, and cannot therefore make any messenger RNA. Dormancy can be ended at any time by supplying the bud with a particular hormone, gibberellic acid, or by a synthetic substitute of that hormone, ethylene chlorohydrin. Treatment with a minute amount of one of these materials causes the buds to grow, the chemical causing a 10- to 20-fold increase in the template activity of the chromosomes of the bud.
We do not yet know in detail how a small molecule can bind to a larger repressor molecule and change it so that it no longer represses. At least, however, the process can now be studied in the test tube, and I have no doubt but that detailed understanding of how a small molecule effector substance brings about derepression will soon be available to all of us.
We may imagine, then, that each gene in the cell is reposing in a repressed state waiting for the proper effector substance to come along and turn it on. Such effector sub-stances are certainly not only hormones, but also everyday metabolites, dissolved gases, perhaps water, specific substances produced by neighboring cells, and so on. We can begin to visualize how the derepression of one gene may lead to the production of material which causes derepression of further genes, and how this may in turn bring about long chains of genetic switching which can in turn result, as they do in fact, in the developmental process.
Let us then consider the developmental process, for ex-ample the case of flowering. The vegetative bud of a plant grows along, producing leaves and stem; genes for making flowers and fruits are all turned off. Their activity is not required for vegetative growth. Suddenly, however, in the case of a short-day plant for example, the leaf sees a short day, a long night. It produces flowering hormone. The flowering hormone goes to the bud and to the meristematic embryonic cells of the bud; there the flowering hormone says to the repressed genes for making flowers, "Genes for making flowers, I have seen a short day. It is time to become derepressed and start our bud upon the pathway to flower development." Once started upon the floral pathway, development flows on, as it were automatically. Further turning off and on of genes must certainly occur during the course of flower maturation, fruit development and seed production, but this all seems to flow on as a consequence of the initial floral induction act. The developmental process behaves as though it were a pre-programmed routine, a pre-programmed sequence written down in the genetic DNA. How can we hope to study in detail this sequential genetic switching which results in programmed developmental processes? Certainly the task will be a vast one. For the present we can, however take one non-destructive approach to the matter. We can think about it. We have tried to approach the question by imagining what directions would suffice to tell the cell how to divide and multiply and ultimately turn into an adult organism with its specific specialized cells in the appropriate and correct places. Let us take for example the apical cell of a stem of a plant in which the bud and all stem tissues arise from a perpetually dividing single apical cell. The apical cell divides into two. What must happen next? Clearly the first thing that must happen is that each of the daughter cells must have some way to find out who is apical, who must go on and behave like an apical cell, and who must be not apical, but must go through the appropriate later procedures and turn into bud and ultimately differentiated stem tissue. Each cell of the initial division must test itself for apical-ness. The cell that finds that it is not apical must then of course find out whether it is time for it to differentiate into the specialized tissues of the stem. How will it find out? It must apparently test itself for the size of the cell mass in which it is embedded, the size of the bud. It tests itself for this size and finds it is a single lone cell at the very top of the bud, surmounted only by an apical cell. The program for stem development presumably says that before cells can start on the pathway to differentiation they must be in a big, fat bud. This is the way it happens in nature. Our first product of apical cell division must therefore divide again. I would imagine that it divides, and divides, the daughter cells testing themselves each time for the size of the cell mass until they find that they have arrived at the size suitable for the bottom of a mature bud. Once they have achieved this size, and have satisfactorily passed the bud-size test, the cells of the bud must make further inquiries. For example, each one must ask itself, "Am I on the outside of the stem?" If the question is answered in the positive they must get out the subroutine which tells them to turn into epidermal cells. If they are not on the outside, they must ask themselves if they are on the very inside. If so, they must turn into xylem, which is on the inside of plant stems.
Using considerations such as the above, we have attempted to model the program by which a single apical cell might develop into an adult plant. To make this program rigorous we and our colleague Fred Mayer have written this program in a form suitable for an electronic computer. This pro-gram, which we call DOGMA, or Digital Organ Generator Model A, if followed by a single apical cell, causes the generation of a bud, the turning of the oldest part of the bud into mature stem tissues, and as long as the program is followed the stem continues to grow in length, always surmounted by a bud and a continually active apical cell. Such modeling gives us insight into the developmental process. It tells us what components must by logical necessity be contained in the developmental machinery of higher organisms. The most important insight into development which the modeling of developmental programs has given us has been the concept of the developmental test. We have seen above that in the case of the bud we must imagine that the dividing and growing embryonic tissue continuously tests itself for size or for number of cells, each time comparing the value found to
a value stated in the program as a desired one. The concept of the test carries us, I believe, to the central core of the logic of differentiation. The growing bud tests itself against the required ultimate size, the same cells test themselves for the presence or absence of flowering hormone; a cell tests its neighbors for strangeness or similarity. In these and a myriad of further ways must we imagine that each cell in a developing organism keeps itself informed of where it is in the developmental path, and what therefore is the appropriate next step. The test as one unit in the logic of differentiation is of course already known as an experimental fact, as in the case of the presence or absence of a hormone in its target organ. All that we do here is to extend the concept of the test to include other kinds of tests which although not yet experimentally known would seem to be essential to the machinery of development. One of the clearest examples of the developmental test at work is provided by the example of the plant embryo. This normally develops, as all embryos do, from a single cell, the fertilized egg, and is carried on inside an ovary full of the chemicals needed in embryonic growth. These two conditions are all that is required to cause a cell to develop into an embryo; the cell must be a single, and it must be surrounded by the ovarian nutrients. Professor Stewart at Cornell University has shown that fully differentiated cells of many types start life anew and develop into embryos if these two conditions are fulfilled. We may imagine that the plant cell is continuously testing itself for the presence of neighbors. As long as it finds neighbors it says, "Aha—here I am—I've got lots of neighbors—I'm sup-posed to lie dormant and not do anything." If it finds suddenly that it has no neighbors it then tests itself for the presence of the embryo nutrients. If the outcome of this test, too, is positive, the cell must say to itself, "Well—gee whiz—it's funny, but here I am all alone and there are the embryo nutrients out there, so I must be a fertilized egg, and I will therefore develop into an embryo."
There is, then, very real hope that biology will in fact be able to describe in molecular detail the several aspects of the developmental process. This knowledge will give us a corresponding control over developmental matters. We can envisage the day when it will be possible to take a cell, any cell, and reset its program to any desired point. It may be-come possible for us to reset the developmental program not to the stage of the fertilized egg, but to some stage further along in the developmental process, and thus to regenerate new organs for example, to replace tired ones, or to generate more organs if the individual wishes more. I have tried to think, for example, about what further organs I would like to have, and I have decided that I would like to have four hands since there is so much for biologists to do. Recently as I was trying to light my pipe in the laboratory my colleague, Professor Huang, said to me, "You have been talking about how you want to have four hands—if you're going to smoke a pipe in the laboratory you'll need five." So, as you can see, we are all very optimistic about the future success of the new, new biology.
Development is then in good shape—much remains to be done, but it all appears to be doable. Its just a matter of hard work and time. What will biologists do next? Luckily, the biggest problem of them all still awaits us. The human brain is the most complex device of which we know, and we understand it very little. We know it consists of ten billion neurons, each a sort of digital device which is arranged to fire an electrical discharge in response to an appropriate array of electrical inputs. We know that the brain is capable of acquiring, processing, storing and retrieving information, and we know that although our DNA causes the construction of the brain machinery, it puts no information into it. On the contrary, the information which our brain acquires, it gathers from the outside world, from our sense organs. We know, too, that different parts of the brain are concerned with different functions, the varied motor functions, the varied sensory functions, the visual, auditory, etc. functions; we know that one part of the brain is reserved for speech and has all the words written down in it, and so on.
In a very real sense the brain appears to be an electronic information processing machine, or rather many such ma-chines, all working simultaneously and in parallel, and all being continuously monitored by a central computer to which we assign the name of consciousness. The consciousness as-signs problems to the sub-computers, and accepts answers to these problems as they are prepared by the slave machines.
It is the next challenge to biology to discover in detail how the brain works. Luckily some of our colleagues are already at work on this matter. One approach to the study of the brain is to model its operation; to try to so instruct an electronic information processing machine so that it be-haves in a human-like way, say in problem solving, in remembering, in speech, and so on. This approach gives us insight into the logic of the neuronal switching network and has already had some successes. We must remember, how-ever, that the very largest electronic information processing machine so far made is far smaller in number of nerve cells than even an illiterate octopus, which in turn is much smaller in number of nerve cells than a human brain. As we get bigger electronic information processing machines, and as we educate them in a more people-like way and over a longer period of time, we should get correspondingly more insight into the logic of brain operation.
A second approach to the study of the brain is electrophysiology, finding out how the nerve cells display in electrical form sensory stimuli, thought and emotions. Certainly we are very far from knowing anything about the electrical representation in our brain of thoughts and emotions. We do know something, however, about the electrical representation of sensory stimuli. Professor Hubei, for example, has already mapped out in some detail the way in which the individual cells of the visual cortex present in the cat's brain the abstracted components of motion in the visual field, and Professor Pogio has similarly mapped out in some detail the electrical representation in the sensory cortex of the monkey's sensation of joint movement. As our methodology improves, we may hope for deepening of our understanding of the way
in which brain activity is represented in electrical discharges by individual neurons and neuronal networks.
And finally there are the problems of the material nature of brain operation. The brain cells are of course made of something. In the case of our man-made electronic processing machines, the individual neurons are the product of solid state physics. The individual units of our brain cells are not solid. We speak, in the case of the brain, of sticky state physics, since they are made of gooey matter. One would like to know, for example, of the way in which memory works. Our understanding of the brain is still so primitive that until recently it was impossible to even suggest a model of what happens when one stores a fact in memory. Let us consider memory for a moment. By memory we commonly mean permanent or long term memory. The scenes and events of childhood last a lifetime, as does also the learned behavior of language. We all know that there are short term memories too. We learn a new word and pronounce it letter-perfect several times, and yet cannot remember it five minutes later. The facts concerning the different kind of memory can be remembered in terms of a model, not necessarily correct, but handy. Our model says that we be-have as though incoming information is first stored in the brain in a temporary way on a display board, or register. Information must be either transferred from this register to others, or it must decay, disappear. The time constant, the half-time for such decay in the register which first receives incoming information, is of the order of a second or less. From the initial register information moves to the second, which possesses a time constant of minutes, perhaps five minutes. Here again, information must be transferred to further registers or decay, and the further registers to which information may be passed, the final registers, constitute the permanent memory. A wealth of experimental and observational details support the three-stage model of our memory machinery, and shows in addition that the short and medium term memories are basically electrical in nature, the long term memory not. Thus the sudden discharge of random electrical activity through the brain as by a blow renders the victim not only unconscious, but permanently removes all memory of events which took place a few seconds before the blow. By such random electrical discharge the short term registers are apparently wiped clean, and denied the opportunity to transfer to the other registers. But the medium term register is itself electrical. Thus, suppose that an experimental animal, having learned something, is subjected five minutes later to electroshock treatment, the discharge of random electrical activities through the brain. The animal instantly loses all memory of its learning. If, however, an hour is allowed to intervene between learning and electroshock, learning persists unimpaired, or nearly so. Something has happened in the interval. The memory has been converted to a new form, a form which is resistant to electrical disturbance, a form in which units of the brain have been somehow or other permanently altered. What is the nature of this alteration? To make our discussion concrete, let us discuss memory in terms of registers in which information is displayed. The register is initially empty, a row of zeros. After something has been learned and memorized, the units of the registers have been reset, by certain of the zeros having been changed to ones. Information is now encoded in the register. Information is displayed. In the permanent memory, the elements of the register are either individual neurons, or more probably individual junctions between neurons. Re-setting of an element of the register means that a change in the properties of that element has taken place. In the case of the short and medium term memories such change is reversible, and in fact reversed by time as well as by electrical activity. In the case of permanent memory, the changes in electrical properties associated with the resetting of the units of the register are permanent ones. The bulk of neuroanatomical evidence indicates that learning and memory are not associated with the formation of new electrical junctions, not associated with, as we say, the soldering of the system. We think rather in terms of changes in chemical properties of the neurons involved. During the last three years, it has become evident from the work of Holger Hyden, John Gaito, and others, that the act of learning and storing information in permanent memory is associated with increases in content of RNA in those portions of the brain which are involved in such learning and memory. John Gaito has done an elegant experiment, for example, in which rats are taught a simple lever-pushing-for-food task. The RNA content of different parts of the cortex of such rats has been compared with those of non-learned rats. The results border on the spectacular. In two regions of the cortex, both concerned with the learning task, two-fold increases in RNA amounts accompany learning of the task. Such alterations in amount of RNA are not found in any part of the cortex. We have, then, quite good reason to suspect that increases in RNA content are associated with those alterations in the neuron or neuronal network which constitute long term memory. What further can we say about RNA and memory? It has of course been suggested that information stored in memory is stored in the form of new RNA molecules which then contain the experimential data written out in RNA language. No thought is so fantastic that the molecular biologist should not try thinking it'for a while. The present thought becomes, however, less and less appetizing as one thinks about it. It requires that information originally encoded in electrical form be transcribed into base sequence form. It requires neurons to manufacture RNA of base sequences not specified by their DNA. This is, as we all know, very anti party line, since in normal cells of higher creatures all RNA is made by DNA-dependent RNA synthesis, and the neurons of the cortex are no exception to the general rule. My own suggestion is that electrical input into a neuron derepresses a particular gene, which is present in the genome of all cells, and whose function it is to be derepressed by electrical activity in neurons, by this particular modality of effector substance. Derepression of such a previously repressed gene would result in increased RNA synthesis as is observed. The gene once derepressed may stay derepressed for evermore, thus causing a permanent change in posture of the unit, a
permanent change in this portion of the register, the encoding of a unit of permanent memory. This hypothesis may be tested in a variety of ways, although such tests have not yet been conducted. It will be exciting to try them out. It would appear that the molecular nature of memory is now a subject ripe for attack.
And so, brain biology is the next great challenge—the challenge to break the brain code. It will be an enormous task, but it is already clear that it can be accomplished. As we get to know more about the way our brain operates we can learn to use it better. We can learn to teach more effectively, to learn more effectively, to think more effectively, to feel more effectively. Our ultimate conquest of the secrets of the brain will come just in time, too, because in the mean-time our (now simple) man-made information processing ma-chines will have become formidable creatures. Remember that the first electronic information processing machine was sold just ten years ago, and see how far they've come in the intervening period. By the time another generation or two has passed, the time that we have full knowledge of our own brains, our man-made information processing machines will have become very smart indeed. They may have even set up research centers for finding out how to improve themselves, as well as biological research centers to find out how they may reproduce themselves, instead of depending upon man. If man is not to become obsolete, he must keep up in the development of his own brain power with the development of these machines which at present are our slaves.
As our understanding and control over our brain grows, it will not be surprising to see appreciable changes in our species. One of the most desired objectives of applied biology is to prolong the health and well-being of the individual human. We are gradually learning to preserve the body, and will no doubt succeed ultimately very well indeed. To pre-serve the body is, however, not so useful unless we can preserve the brain, and this is today a problem. We are each of us born with ten billion nerve cells, but our brain does not have the ability to add to this initial endowment. Furthermore, our brain cells gradually die. After the age of 35 we lose a hundred thousand or so per day, and after a sufficient number of years we begin to notice the deprivation. We grow absent-minded and forgetful, and ultimately attain the mental senility of old age. How nice it would be if we could but mate our new knowledge of developmental biology to our knowledge of brain biology, and encourage a judicious multiplication of the neurons of the brain, a multiplication which would take place in just sufficient amount to balance neuronal loss. These new neurons will of course have no information stored in them initially, but we can fill them full of information since in the generations to come we will be learning continuously throughout our lives. Even today we must, it is said, spend a third of our time in continuing education or we become intellectually obsolete. By such continued retraining, our new neurons can be scuffed full of newly acquired information and made useful. By such strategy we may hope to keep man alert and intellecntally productive for a larger portion of his life span. We may even ultimately be able to produce theoretical physicists who are productive at the age of 60.
As our conquest of the brain approaches completion, it will not be surprising either if mankind begins to wish for new kinds of sense organs, sense organs not granted to us heretofore. How nice, for example, to have receptors and transmitters for microwave transmission of information, so that we may talk and listen to people at a distance. It will doubtless become possible ultimately to directly wire such new sense organs into the appropriate junctions of the cerebral network, so that they operate directly upon the cerebral network, just as do our present organs of hearing and speaking.
The brain is today about as big as we can handily carry about. If it were twice as large it would be quite a load. Even so, people of the future who will depend even more than we do today upon full exploitation of their brainpower, will doubtless want to have bigger brains. We will think, in these days of the future, of growing our brains larger, and this will be possible because we will be able to leave them at home. With the development of sense organs for microwave communication there will be no reason why the individual sense organs cannot be made independent so that they can travel on their own, transmitting their acquired information to the brain by microwave. The brain will stay at home in a warm, comfy room, concentrating its efforts on thought, while the sense organs roam the world, seeing, talking, listening, playing—and continuously in communication with the head office. We will enjoy a new freedom—freedom from carrying the head around.
Finally, and this will doubtless come in the days of the next, next, new biology, after our understanding of self-duplicating information processing machines is rather complete, we may very well give thought to the question of whether the gooey, sticky things of which we are made, nucleic acids, proteins, lipids, and the like, are really the most suitable construction materials for such highly sophisticated, long-lived creatures as mankind will then be. People will say things like, "Maybe a silicone backbone with four different markers would be better than deoxyribose and phosphodiester bonds. It would be less susceptible to cosmic rays and more resistant to attack by the strange new organisms which have just been found on the moons of Jupiter." And doubtless, too, there will be enthusiasm on the part of some vocal minority group for going over to a decimal genetic code, rather than a four letter one. I can just imagine the Dupont Company of that day beating the drums for their own replacement chemicals, "Better Living Things Through Chemistry" will be the slogan of the Dupont Company of that time. Man will have the opportunity to literally remake himself in whatever image he chooses.
And so, I see the next greatest of challenge as the exploration of ourselves, the acquisition of a full understanding of that wonderful instrument which makes biology, and indeed science, possible—that marvelous device which we call our brain.
Notes from the Editor
Following my note in the last issue of the Bulletin, Dr. James L. Walters (University of California, Santa Barbara) called my attention to a highly pertinent essay on the word "protoplasm," published by his colleague, Dr. Garrett Hardin, as well as a rebuttal to Dr. Hardin's paper. In 1960 the AIBS published a brochure by Dr. Hardin, "Do we need the word protoplasm?" covering this topic, as an adjunct to its secondary school biological sciences film series. This brochure and the following two papers should be of interest to anyone wishing some additional views on "the word."
Hardin, Garrett. 1956. Meaninglessness of the word proto-
plasm. Scientific Monthly 82: 112-120.
Walker, Roland. 1956. The meaning of protoplasm. Scientific Monthly 83:35.
Dr. Walters has further called my attention to the classic essay by Pirie, which, as he suggests, is pertinent to this discussion:
Pirie, N. W. 1938. The meaninglessness of the terms Life and Living. In Perspectives in Biochemistry, pp. 11-22. Cambridge University Press.
We are pleased to announce that the National Science Foundation has approved the University of Massachusetts' proposal for the Botanical Society's Sixth Summer Institute, scheduled for June 20 to July 15, 1966. Additional details will be provided in the next issue of the Bulletin. Anyone wishing to be placed on the mailing list for an early copy of the Institute's brochure should write to Dr, Edward L. Davis, Department of Botany, University of Massachusetts, Amherst.
Dr. S. N. Postlethwait of Purdue University, Chairman of the Committee on Education, will soon be sending each member of the Botanical Society a questionnaire on "tachy" plants. The CUEBS Panel on Instructional Materials and Methods is sponsoring and financing this project. Dr. Clarence E. Taft of Ohio State University and Dr. Richard M. Klein of the New York Botanical Gardens are cooperating with Dr. Postlethwait in the survey. For the enlightenment of the uninformed (which recently included the Editor of the Bulletin) "tachy" plants are "rapid" or "speedy" plants, being those that can complete their life cycles within relatively short periods. Arabidopsis thaliana is probably the most widely used "tachy" plant at the present time.
Problems of Botanical Terminology
EMILY T. WOLFF
Hobart and William Smith Colleges
In the October issue of the Plant Science Bulletin, Dr. Howard Stein proposes that a committee be established to consider the problem of botanical terminology and to make specific recommendations. That is probably the most efficient way to revise and improve the legacy of terms which are becoming burdensome to the field of general botany. The problem is not new, of course, nor is it peculiar to botany.
New discoveries and new ideas require a continual coining of terms which must have limited and precise meanings. The problem arises when these terms, so necessary in the specialized fields, are accepted uncritically by both authors and professors, who present them, in turn, to the beginning students.
Consider the situation of those studying introductory botany in liberal arts colleges. The overwhelming majority of such students have no intention of doing any advanced work in botany; rather, they elected botany because it seemed to offer some promise of being an interesting way of fulfilling a part of their science requirement. From their point of view, any simplification of the terminology would be a step in the right direction. They are interested in learning about plants, rather than in the terminology applied to plants.
Obviously, we cannot do away with strictly botanical terms, nor would we want to. As in any field of knowledge, it would be impossible to get along without some of them at every level of discussion. However, because we have such an immense amount of botanical knowledge worth teaching, our botanical vocabularies ought to be reevaluated with reference to their appropriateness in the beginning courses.
In our introductory courses, we aim to present the major ideas of biology. One of the most important is evolution, as suggested by a basic similarity in cell structure, metabolism, and reproduction in the different plant groups. When, as is too often the case, we use unique sets of terms for particular plant groups, we are obscuring the real aim; we then are emphasizing differences between the plants, rather than their similarities. A set of terms which could be applied to all plant groups would make it easier for the students to understand that we consider all structures bearing the same name to be homologous. For instance, gametophytes should be called gametophytes in every case, regardless of whether or not the students pick up the more specialized terms, Iike protonema or prothallium or embryo sac. Similarly, megasporangium is to be preferred to =cellos. Oogonium has much to recommend it as a general term for any egg-producing structure, in spite of accepted usage; one unfamiliar with botanical literature might assume that archegonium applies to the more primitive and more general structure. Many botanists believe that we need both terms, although the single term antheridium, for a sperm-producing structure, has presented no difficulties. We might consider giving a wider meaning to spermagonium, which now has a very limited application.
A related topic concerns the number of spore types recognized in introductory texts. Currently, there are more than 20 terms in common usage. Some are indispensable (e.g. ascospore, basidiospore, teliospore), while others are of doubtful value in a general course (e.g. akinete, aplanospore, auxospore, carpospore, chlamydospore, oidium, sporidium, swarm spore). A few well-chosen terms would serve better than a multitude.
A generation ago, a uniform terminology would have been impossible, but perhaps we have enough information now to attempt a revision. There is really no incentive for textbook writers to make more than a few minor changes in the usual presentations. Left to the authors of general texts, it might
take a generation or longer to effect changes that should be made soon. A responsible committee might be able to hasten these improvements.
News and Notes
The Fifth Summer Institute for College
One of the important ancillary functions of the Botanical Society of America is the sponsoring of summer institutes for college teachers of botany. In the summer of 1965 The Botanical Society, with the financial aid and encouragement of the National Science Foundation, sponsored such an institute at Michigan State University in East Lansing. It was my pleasant privilege to be the Director of this particular institute, and I would here acknowledge the help given by Dr. Adolph Hecht, Dr. John Mason of our Science and Mathematics Teaching Center, Dr. William B. Drew, the Chairman of our Department of Botany and Plant Pathology, the staff of the Horticulture Department, and by members of the University Business Office.
The work of the Institute started in February with the selection of topics, the invitations to the lecturers, and the printing of brochures and their distribution to representative colleges. Notices were sent to various biological and botanical magazines. Not long after the brochures were mailed, inquiries and requests started arriving. While these were being handled, the final appointments to the staff were made, and supplies for each week were ordered, in accordance with the requests of the lecturers. Equipment, not purchasable on the grant, was located so that it could be borrowed at the proper time. Busses were scheduled for the field trips and rooms arranged for the lectures and laboratories. Flats of seeds had to be planted weeks ahead of the laboratories.
Since more than five times as many applications were received than there were places available, a system of grading and evaluation had to be established. The top applicants were then notified that they had been accepted and an equal number notified that they were alternates should any of the top candidates 'decline to attend the Institute. Since most of the alternates declined to be an alternate, the Director only hoped he would not find himself faced with unfilled spots. All of the remaining applicants were notified that they could not be accommodated.
The successful applicants, now called participants, were then sent a mass of materials including maps of the campus, lists of local churches, recreation facilities, and suggestions for reading materials. Between this time and the first day of the Institute, the typical Director feels much like a gambler would, hoping that he has covered his bets and that a full crew of lecturers and participants will show.
It would be too tedious to recount every detail of the operation of the Institute once it actually started, but suffice it to say that a modicum of planning must go on, looking several weeks ahead. As far as I know, the mortality rate for Directors is extremely low, and most manage to survive the sometimes pleasant task.
We received 300 requests for brochures and blanks. One hundred and forty-six applied, and 27 were accepted plus two sent to us by the NSF on their foreign-participant program. These participants came from 17 states of the Union and from three foreign countries. Twenty of the 29 had Ph.D. degrees, and the remaining nine had masters' degrees. The intelligence of the group varied about an unknown, and hence undisclosable, mean, but none of them could be considered subaverage. All were fine, earnest people, anxious for knowledge about the latest advances in the various aspects of botany.
The lecturers were drawn from various parts of the United States and Canada, but some local experts were used. A few of the lecturers donated their time, and for this we were very grateful. It might be of some interest simply to list the topics covered in the lectures and laboratories so that the members of the Society may have some concept of the coverage. The topics were developmental anatomy, the history of cytology, chromosomal configurations and their use in cytogenetics, developmental morphology including treated callus cultures and the effects of light on growth, chemical taxonomy including practice in making chromatograms and their use in systematic studies, the present status of radiation studies on plants, mod-ern concepts on photosynthesis and respiration, trends in ecology, the contributions of horticulture to botany, carbon dioxide and plant growth, the collection and identification of plant fossils, fossils and evolution, coal ball peels, the history of genetics, techniques in the extraction and use of RNA, medical mycology, recent work in mycology, uses of algae, detection of virus diseases by their symptoms, plant pathogens in the soil, the collection and identification of mosses, the shoot apex in ferns, sterile culture techniques in fern research, and the contributions that physics can make to botany, especially in regard to photosynthesis. Other matters were discussed and field trips were taken, but enough has been said to give the reader an idea of what a Summer Institute might cover. My personal opinion is that such institutes as the one outlined are very worthwhile and perform an important service to the science of botany.
In closing, I wish especially to reach the department chairmen in botany and beg them to open their facilities to such institutes in the future. The NSF offers scores of summer programs, but this particular type is the only one servicing all of the facets of botany. The physical sciences and the animal sciences are pushing hard for funds to upgrade people in their fields. They are getting the bulk of the NSF money for institutes. Do we not have something to offer?
Irving W. Knobloch
Michigan State University
The Teaching Section
The increasing number of Botanical Society members listing an interest in botanical teaching in the 1965-66 Year-book attests to a growing awareness of the importance of teaching and the opportunities for improving our present methods of instruction.
In view of the near-capacity attendance at the Teaching Section's symposium, panel discussion, and presented papers' sessions at the Urbana meetings last August, plans are already
being made for the Section's forthcoming meetings at the University of Maryland. Individual teachers who feel that they are doing an outstanding job in some unique and refreshing way should begin thinking of the possibility of sharing these procedures with others by participating at the coming sessions.
Officers of the Teaching Section elected for the coming year are: Chairman, Paul A. Vestal; Vice-Chairman, Helena A. Miller; Secretary- Treasurer, J. Louis Martens; and A. J. B. Editorial Board Representative, Harriette V. Bartoo. For the Maryland meetings, Dr. Martens, Illinois State University, Normal, Illinois, will receive abstracts for the Teaching of Botany Section. Those planning to present a paper should communicate with him well in advance of the deadlines that will soon be announced by the B.S.A. Program Chairman for the submission of titles and abstracts. Members of the Botanical Society who wish to affiliate officially with this section should write to the Secretary-Treasurer.
J. Louis Martens, Secretary-Treasurer Teaching Section, B.S.A.
Sustaining Membership Committee
The Sustaining Membership Committee, composed of 30 members from all parts of the United States (and its possessions), worked very hard to launch the campaign. The Committee sent out some 350 letters, individually typed, to presidents and heads of businesses.
As a result the program starts with five sustaining members, and considering the fact that other societies, long in the sustaining membership program, have from 10 to 20 sustaining members, the program has started relatively well.
The five sustaining members are:
The Chairman wishes to thank the members of the Committee for their hard work, clever ideas and devotion to the goal. He wishes especially to thank Robert M. Giesy of Ohio State University for his aid in creating the letter that was used.
Membership of this committee included the following persons: Vernon Ahmadjian, Catherine H. Bailey, Sandra L. Bell, Donald E. Bianchi, Jack M. Bostrack, Richard G. Bowmer, Bert G. Brehm, James L. Brew baker, Joe H. Cherry, Arthur W. Cooper, Tom S. Cooperider, Bradner W. Coursen, Temd R. Deason, William H. P. Emery, Sister M. Veronica Fasbender, Richard T. T. Forman, Raymond A. Galloway, J. H. B. Garner, Robert M. Giesy, Charles S. Gowans, Barton E. Hahn, H. David Hammond, H. Keith Harrison, Raymond W. Holton, Richard M. Klein, Charles C. Laing, B. T. Lingappa, Bruce Parker, Gene A. Pratt, Jaime Rosado-Alberio, Howard J. Stein, Francis R. Trainor, Michael Treshow, Kenneth A. Wilson, Joseph M. Wood, Victor B. Youngner.
Lawrence J. Crockett, Chairman
Sustaining Membership Committee Minutes of the Business Meeting
President—Harold C. Bold, John N. Couch, Lincoln Con-stance.
Vice President—Ralph Emerson, Warren H. Wagner, Jr., F. C. Steward.
Editorial Comm. (1966-1968)—Anton Lang, Norman H. Boke, Robert M. Page.
A motion was made, seconded, and carried unanimously that the candidates with the highest number of votes in each category be elected. The officers for 1966, therefore, are:
President: Harold C. Bold; Vice President: Ralph Emerson; Ed. Committee: Anton Lang.
and his Committee for their outstanding work and accomplishments.
8. The Secretary announced that reports from the various Topical and Geographical Sections had been received and that these reports would be placed in the archives of the Society along with the Minutes of the Business Meeting.
9. In the absence of Dr. Ralph Wetmore, Chairman of the Committee on Election of Officers, the Secretary presented a report from this Committee. Although amendments had been presented this spring in a mail ballot to the membership, the Committee had actually been instructed to present its findings to the 1965 Council, at which Council the proposed amendments would be put into final form for submission to the membership. At the Council Meeting on Sunday, the 15th of August, the Council had gone over the proposed amendments and made certain changes. All the amendments which had been previously circulated to the membership and which had received the majority of approval would be resubmitted in their new form; however, to protect the Society the Council recommended that Amendments XI and XII, dealing with the use and disposal of revenue by the Society, be voted on at the present meeting even with wording that was not completely acceptable. After proper motions Amendments XI and XII were accepted as follows:
Article XI. General Prohibitions
Notwithstanding any provision of the Constitution or Bylaws which might be susceptible to a contrary construction:
The prohibitions contained in this subsection (7) do not mean to imply that the Association may make such loans, payments, sales, or purchases to anyone else, unless such authority be given or implied by other provisions of the Constitution or Bylaws.
Article XII. Distribution on Dissolution
Upon dissolution of the Association, the Board of Governors shall distribute the assets and accrued income to one or more organizations as determined by the Board, but which organization or organizations shall meet the limitations prescribed in Sections (1)-(7), Article XI immediately preceding.
10. The President announced that the Summer Institute for College Teachers of Botany was planned for the University of Massachusetts in 1966 and that a proposal had been submitted to the National Science Foundation by the University of Massachusetts for this purpose.
"Be it resolved that the Botanical Society of America is grateful to Dr. Dominick Paolillo and his colleagues at the University of Illinois for their efficient management of our meeting and for the excellent facilities provided."
Richard C. Starr, Secretary Botanical Society of America
Rudolf Florin 1894-1965
The death of Professor Rudolf Florin, Swedish paleobotanist, has terminated one of the most remarkable and productive botanical research careers of modern times. For more than 40 years Professor Florin had focused his attention on conifers and taxads. Although he has been regarded as primarily a specialist on the fossil members of these groups, he was strongly aware of the fact that problems of morphology and phylogeny could be effectively dealt with only when all evidence is taken into consideration. Consequently living conifers and taxads came in for a major share of attention. Much of his research material was the cutinized epidermal fragments that are sometimes retained on compressed fossils, and which by utilization of proper techniques can be studied. Although fossilized cuticles were known to exist long before Professor Florin began working with them, detailed studies of this seemingly unpromising material had been attempted
only in a few isolated instances. Even less attention had been paid to epidermal characters in taxonomic studies of living taxads and conifers. On the basis of distinctive characters revealed by the epidermis Professor Florin was able to recognize several new extinct forms, and he even named a few new living genera, Pilgerodendron and Nothotaxus being examples. Much credit, therefore, goes to him for revealing the possibilities of cuticle characters in taxonomy, not only of fossil plants, but of living ones as well.
Professor Florin has left an impressive list of publications, impressive not only for the length of certain numbers and the scope of the subject matter, but for general excellence and the extraordinary amount of painstaking research revealed. If some particular one of his publications were to be singled out as especially outstanding, it would unquestionably be "Die Koniferen des Oberkarbons and des unteres Perms" which appeared in eight parts in Volume 85B of Palaeontographica between 1938 and 1945. This work consists of 729 quarto size pages and 186 plates. While executing this formidable task he also found time to prepare the most extended contribution ever written on fossil Ginkgoales, "Die fossilen Ginkgophyten von Franz-Joseph-Land," published in Volumes 81B and 82B of Palaeontographica and embracing 254 pages and several plates. In the meantime, and subsequently, there appeared under his authorship important papers on cycadophytes and other plants, mostly being the results of research with cutinized material One particular feature was his stress on the taxonomic significance of the relation of the guard cell pairs to the encircling cells when considered in conjunction with other features of the epidermis. One legacy of these studies is two technical terms, haplocheilic and syndetocheilic, which specify whether the guard cell pairs and their encircling cells develop independently of each other or from a common mother cell. Another major contribution was to show the undoubted homology between the cordaitean inflorescence and a modern coniferalean cone, thus settling a controversy of long duration.
In addition to the many honors and citations Professor Florin received in his own country, he was made a Corresponding Member of the Botanical Society of America. In 1949 he gave the Prather Lectures at I-Iarvard University, and in 1960 he gave a series of lectures at the University of California under the Hitchcock Foundation. The latter are contained in his last major publication "The Distribution of Conifer and Taxad Genera in Time and Space" (Acta Horti Bergiani, Bd. 20, pp. 121-312, 1963). In 1954 he became the first president of the International Organization of Paleobotany, and was made an Honorary Member of it in 1964. His last professional appointment was the directorship of the Bergianska Trādgārden at Stockholm, a post he held until retirement in 1964.
Professor Florin's personal qualities will always be re-membered and cherished by his colleagues everywhere. He was congenial, but quiet and humble. His cordiality and ease with which he adapted himself always made him a welcome guest. Whenever called upon to act as host, his hospitality was without restraint. He was entirely free, however, of obsequiousness. Although argumentation was not an obsession with him, he would enter into discussion with enthusiasm. But through it all, even when confronted by opinionated individuals holding strongly divergent views, he would maintain his composure and amiability which were so characteristic of him. Coupled with these traits was the ability to think clearly and independently, both of which are strongly revealed in his writings.
C. A. Arnold
University of Michigan
NIH Grants Brochure
A new brochure, Review and Approval Procedures, Public Health Service Grant and Award Programs (PHS Publication No. 909), may be obtained by writing to the Information Office, Division of Research Grants, National Institutes of Health, Bethesda, Maryland 20014.
Current procedures described in the new brochure are of interest to the scientific community in view of the vast number of grant applications received each year by PHS and the extent of federal support of biomedical research. The description includes the process of initial review and recommendations made by study sections and committees for further consideration by the national advisory councils. Applications reviewed by these groups include those requesting support of research projects, research fellowship and training grants, and construction of research facilities. These groups, which meet three times a year, provide the expert and objective advice necessary to maintain the highest scientific standards in the prosecution of PHS research support pro-grams in the national interest.
Dr. Lyman B. Smith, formerly Curator-in-Charge of the Division of Phanerogams in the Smithsonian Department of Botany, has been appointed Senior Scientist in that Department. This appointment will relieve Dr. Smith of all administrative duties and permit him to devote full time on his research to prepare a monograph on the Bromeliaceae. Dr. John J. Wurd&k has been made Acting Curator-in-Charge of the Division of Phanerogams. Dr. E. Yale Dawson has joined the Department of Botany staff as Curator in the Division of Cryptog`r~ams. Dr. Dawson is an eminent algologist with special interests in the red algae and benthic marine algae in general. His main task other than his personal re-search will be to develop the algal collections of the Smithsonian and plan an extended program of algal research.
Dr. Haig Dermen, having recently retired from the U.S. Department of Agriculture, will be available for seminars for students and faculty of departments of botany, horticulture, and genetics on the subjects of his specialties: colchiploidy, cyto- and genetic-chimeras, variegations, cytohistogenesis and the cytogenetics of fruits. He will continue in his cytological work as a collaborator of the USDA, and hence his address will continue to be the same as listed in the Botanical Society Yearbook.