Plant Science Bulletin archive
Issue: 1959 v5 No 5
PLANT SCIENCE BULLETIN
A Publication of the Botanical Society of America, Inc.
VOLUME 5 DECEMBER, 1959 NUMBER 5
Understanding and Control of Plant Growth and Disease'
PLANT SCIENCE BULLETIN
SYDNEY S. GREENFIELD, Editor
40 Rector Street, Newark 2, New Jersey
GEORGE S. AVERY, JR Brooklyn Botanic Garden
HARLAN P. BANKS Cornell University
HARRIET B. CREIGHTON Wellesley College
SYDNEY S. GREENFIELD Rutgers—The State University
PAUL B. SEARS Yale University
DECEMBER, 1959 e VOLUME 5, NO. 5
CIIANGES OP ADDRESS: Notify the Treasurer of the Botanical Society of America, Inc., Dr. A. J. Sharp, Department of Botany, University of Tennessee, Knoxville 16, Tennessee.
Subscriptions for Libraries and persons not members of the Botanical Society are obtainable at the rate of $2.0o a year. Send orders with checks payable to "Botanical Society of America, Inc." to the Editor.
Material submitted for publication should be typewritten, double-spaced, and sent in duplicate to the Editor.
We have received a number of suggestions that Plant Science Bulletin ought to contain a greater amount of news and notes on the professional activities of its readers. Botanists are interested in knowing what their colleagues in other institutions are doing, but not enough news items are submitted to keep them well informed. Some have suggested that the system of regional correspondents that we have been using tends to discourage rather than encourage the reporting of local news.
It has been suggested that one member of each department might act as news correspondent for that department, and in cases where there is only one botanist, that he send in news directly. We are considering abandoning our system of regional correspondents in favor of institutional re-porters and welcome your comments on this matter.
In the meanwhile, there is no reason why we should not receive news and notes from individual members or institutions. On the contrary, we solicit such items from our members in the United States and other countries. Please send us news about books that you are publishing, awards, grants received, honors, special assignments, expeditions, etc., for publication in Plant Science Bulletin.
Understanding and Control of Plant Growth and Disease
(Continued from page I)
successfully pursued to answer questions about the rate and nature of mutation under experimental conditions. In other instances mutations causing gain or loss of single enzymes were traced to changes in single genes, and the one-gene, one-enzyme hypothesis was proposed. The goals suggested are still being actively pursued. For example, fungus mutants deficient in certain enzymes or vitamins are useful analytical tools, and additional ones are constantly sought.
Heritable changes not explainable by mutations or segregation during meiosis also crop up. These changes are being studied by mycologists, plant pathologists, and biochemists. They have learned that multinucleate cells of certain fungi contain nuclei of several different genotypes. These cells seem to induce a higher rate of increase in nuclei of one genotype than of another. In effect, the fungus produces more nuclei that contain genes best adapted for new environments. This concept of a flexible genetic system unique in heterocaryotic fungi was not widely recognized until the last decade. It opened up many corollary problems such as how to validate the details of this genetic system; how to use our growing knowledge to develop new strains of useful micro-organisms; and how to use new concepts to help understand the constant shifting races of plant pathogens.
Probably viruses are more widespread in plants and animals and limit efficient production more than generally recognized. For example, the cause of progressive decline in grape production in eastern United States was not apparent until recent discovery there of the virus causing Pierce's disease. Recent citrus-rootstock studies revealed that many apparently healthy grapefruit and orange trees harbor several viruses that cause serious diseases on certain scion-rootstock combinations. Unwitting distribution of these viruses in propagating stocks resulted in much infection in orchard trees of horticultural varieties in some areas. Barley false stripe, long considered a "physiological disorder," is now known to be caused by barley stripe mosaic virus, to be seed-transmitted, and to be widespread on many species in this country. A disorder in sugar beets in California, formerly known as Salinas yellows, is identified as virus yellows, a disease serious in Europe for many years. Records indicate that the yellows virus caused decline of sugar beets in Colorado as early as I940.
Like others, we desire to understand the nature of viruses and their manner of infection, multiplication, and traversing plants. Others might be thus stirred to understand virus multiplication as a life phenomenon. Any small increase in knowledge takes us one step nearer an understanding of the nature of viruses; within the year we learned that some viruses pass through living membranes and use tracheary water streams as pathways within plants.
We know that hormones within plants control growth and have synthesized several hundred compounds that control growth when fed into leaves, stems or roots; but we do not have the faintest understanding as to how these act. One might say that we stumbled on information that causes us to wonder what we might find by looking further.
We have made long strides toward chemical control of most plant behaviors and can chemically regulate plant growth in many ways of practical value, but we have little understanding of mechanisms involved. The challenges in-crease as new regulators and new ways of controlling plant behavior are discovered. One challenge is how gibberellic
acid accelerates elongation of plants and in some instances eventually increases the solid matter or how a quaternary ammonium compound induces plants to remain short. A greater challenge is the nature of the primary plant reactions to these remarkable stimulants. Actions of the regulators perhaps parallel chemical regulations involved in the expression of hereditary characteristics, which, in the broad sense, represents chemical control by genes.
Green plants are the only chemically productive organism in the earth's population; they are self-supporting, or autotrophic; they alone enable animals and hetrotrophic plants, fungi, and most bacteria to subsist. Green plants accumulate chemical energy, while other organisms dissipate energy. Photosynthesis, by which plants accumulate energy, has received much recent attention. Significant advances in understanding have opened new avenues for inquiry, but the elemental problem of energy transfer from radiation to chemical synthesis by all chlorophyll-bearing plants remains a major unsolved problem. Although research on photo-synthesis has not been well supported, because no immediate crop-improvement benefits were envisioned, everyone knows that a complete understanding of the process would benefit all science.
Another light response of plants, photoperiodism, has received much attention by agricultural scientists. We know many important facts about the photoperiodic reaction con-trolling flowering, the action spectra for long- and short-day plants, the responsible wave lengths of light, and the stimulus to flower perceived by the leaf and transmitted to the meristem; but we do not understand the basic differences between classes of plants. We know that a continuous dark period of determinate length is necessary for modification of the meristem of a short-day plant from a vegetative to a flowering structure; yet a long-day plant blooms under continuous light and a day-neutral plant under light of any duration. We know little about the mechanism of a plant's capacity to measure the passage of time: the red, far-red photoreversible reaction that controls flowering in long- and short-day plants does not regulate flowering of the day-neutral tomato, but it controls its other responses such as seed germination, stem elongation, and fruit coloration. Our present knowledge of the photoperiodic reaction is useful in the commercial production of flowers and fruits and in breeding plants such as soybeans for specific regions, but complete understanding of flowering would greatly simplify the practices.
The importance of dormancy in the life cycle of a plant cannot be over-emphasized. It may last only a few days or too years or more in some seeds. If we could hold all our fruit and nut trees dormant until all danger of cold damage had passed, we could prevent the large crop failures that periodically occur, and if we could induce dormancy in short-lived seeds of some vegetable, ornamental, and other crop plants, we could maintain adequate viable seeds more cheaply.
Dormancy is widespread in weed seeds and in many species is broken only by light. This partly explains the successful use of pre-emergence herbicides and the reappearance of weed seedlings after every cultivation. Dormancy of some seeds, such as lettuce, is induced by unfavorable temperatures, and the seeds in soil and thus in the dark remain dormant after temperature becomes favorable. Given light, however, seeds germinate immediately. 'We have some insight into the way light operates to produce or eliminate dormancy in seeds, but we lack knowledge of the reactions leading to light-induced germination.
Dormancy in most woody plants can be induced by short photoperiods even at temperatures of 70° to 200 °F. Japanese larch, yellow poplar, and others become dormant after about 15 short days, and many species cease growth after about 30; but plants like Monterey pine require several months of short photoperiods. Depth of dormancy is greater in some species, such as catalpa, than in others. Catalpa requires a cold period to break dormancy, but even after a full year dormancy in birch can be broken by long days alone.
With this range of material and knowledge of how to manipulate dormancy we should be able to learn more about the biochemistry of processes leading to dormancy and its decline. Further study of the biochemical processes involved in juvenility of crop trees is also important.
Though inheritance has long served plant breeding, its nature is still unknown. Examination of this subject still shows only much successful empiricism. In a given situation we rely heavily upon selection, when we need promptly to introduce disease resistance into species or genera with-out it.
Classical genetics has dealt primarily with genes producing characteristic phenotypic effects qualitatively classifiable into discrete classes. The effects of such genes have been of great value in development of genetic theory. How-ever, most genes do not produce discrete distributions. Many economically important traits segregate and produce a continuous distribution. Then many loci are seemingly involved, the effects of the individual loci are small, environmental effects are relatively large, and most procedures appropriate for classical genetic analysis are of limited value. The alternative approach is statistical through use of means, variances, and covariances. Competence in this field requires training in statistics and genetics. Because this combination of skills is not common, study of quantitative and population genetics has not been popular.
Plant breeding is merely the application of classical and population genetics. Since population genetic theory is in-adequate, breeding procedures are largely empirical. This empiricism has been largely successful, but the progress does not necessarily indicate the efficiency of the methods. The achievements may be only results of great efforts.
Before we can expect major improvements in plant-breeding technics, we must have a clearer concept of gene be-
havior and relative importance of type of gene action, nature and cause of mutations, genetic structure of populations, magnitude of interaction effects, and relative magnitude of genetic and environmental effects. Such information is basic to the development of efficient breeding systems. Systems of maximum efficiency may well differ for (I) self-pollinating species, in which the end product is an inbred line (small grains, soybeans, etc.); (2) cross-pollinating species, in which the end product is a first-generation hybrid (corn, onions, etc.); and (3) a vegetatively propagated species like potato. Because of past differences in evolutionary pattern and selection history, each of these types might have a somewhat different genetic structure. The problem is further complicated by the fact that degrees of importance of genetic interactions depend upon the stage or level of improvement. If this situation is general, different breeding procedures may be required at different levels of improvement. In conclusion, I have cited a few of the unsolved problems confronting plant scientists. Major progress in any of these areas has great effects, not only on basic knowledge but also on agriculture. Further study of these and similar concrete problems will lead to a gradual elucidation of broader and intangible unknowns.
In his interesting and clever article entitled "Botanical Research—The Next 50 Years", in the April, 1959, Plant Science Bulletin, Dr. Thimann remarks on the "unexpected and rather mysterious sight" of a taxonomist transplanting seedlings, and points out that taxonomy, morphology, ecology, and other descriptive sciences have developed experimental aspects. He welcomes these developments, as we all do, since they increase our knowledge and understanding. But then he goes on, hopefully, to ask "what is the betting that in another generation or less these will be the only kind of Taxonomy, Morphology, Ecology, etc., extant, and the old descriptive kind will be largely obsolete?"
One could scarcely ask for a better example of the narrowness and smugness that seems widely characteristic of mod-ern experimental biology. It might be asked, after ecology has moved into the phytotron and observational ecology has become obsolete, what then would be the meaning of ecology? Presumably, textbooks would be written and courses offered on the ecology of plants in phytotrons. Common people who happen to have a curiosity about how plants behave in the outdoors would, presumably, have to observe them and figure it out for themselves.
At the Montreal Congress Wm. T. Stearn made the estimate that there may be 250,000 species of vascular plants. E. B. Babcock, one of the best of the experimental taxonomists, working under the best of conditions, with excellent international cooperation, and with the aid of a first class younger taxonomist, since turned experimental, spent 30 years producing a monograph of Crepis, a genus of about 13o species of short-lived plants. I-Ie admitted that the mono- graph, although as far as possible experimental, was still largely a herbarium study, since he had been able to get only 90 species in culture. At the rate of 130 species per taxonomist per 30 years we would need at least 1923 taxonomists with assistants, working both experimentally and in the classical manner to monograph all the plants in a generation, even if all plants were short-lived herbs, which most of them are not; the bill for the facilities needed for this experimental work would be rather large-sized; and, while this vast program is going on we wonder who will make all of the identifications of plants needed by the public, the foresters, the gardeners, and others interested in plants, including even occasional physiologists. Perhaps we will have electronic brains to do this. Certainly the experimental taxonomists will be too busy and the rest of us will be obsolete.
F. R. FOSBERG Falls Church, Va.
When I said that taxonomy, morphology and ecology might become wholly experimental in the next two generations, I was making a guess at the general trend, not presenting my own feelings. So if there is "narrowness and smugness" this is a property of a rather large group of botanists. The answer to Dr. Fosberg's question is, of course, that plants will be identified by those who have the best knowledge of the group or genus, and if it seems that experiments are needed to gain this, the experiments will be done. Of course botany will not go into suspension in the meantime.
KENNETH V. THIMANN
The National Science Foundation will award grants to defray partial travel expenses for a limited number of U. S. scientists who wish to participate in the Second International Congress of Bioclimatology and Biometerology. This Congress is scheduled to meet in London, England, September 5-10, 1960. Application blanks may be obtained from the National Science Foundation, Washington 25, D. C. Completed application forms must be submitted by March 1, 1960.
Dr. John Franks, Manchester Museum, The University, Manchester 13, England, is interested in the exchange of herbarium sheets. He has a large number of duplicates made by well known European collectors of the 1800's from localities no longer available. He is interested in receiving North or South American collections of recent vintage that are accompanied by adequate data. His material covers all plant groups.
A new publication series entitled "Occasional Papers of the C. C. Adams Center for Ecological Studies" has been founded. The first number will appear in late 1959 or early 1960. Persons or organizations interested in being placed on the Center's mailing list should contact the Director, C. C. Adams Center for Ecological Studies, Western Michigan University, Kalamazoo, Michigan.
In reply to the statement by Trilochan S. Bakshi in your Bulletin, Vol. 5, No. 1, March 1959 that "it would have made a world of difference for all scientists the world over" if I —Laessle (1958) had used "Pinus palustris/Quercus cerris" in place of the common names "Longleaf pine/Turkey oak," I should like to state that indeed it would have made a "world" of difference. Whether Dr. Bakshi was being facetious in citing Willis (1951) to convert turkey oak to Q. cerris, a species native to S. E. Europe I do not know, but it is certain that if I had used Pinus palustris/Quercus cerris for the name of my association I should have fallen into a double error for P. palustris (Small, 1933) is slash-pine, a tree confined to swamps and wet areas. The common name of longleaf pine is not, and has not been, applied to any other species, but the scientific name has long been con-fused. Pinus australis, as used by Fernald (1950) is more recent than the (1949) authority cited by Bakshi and is much more generally used.
Speaking seriously, I do approve of Dr. Bakshi's thesis, and I would gladly have used scientific names for the associations if there had been any complete and modern source for them. Work is in progress but it may be at least ten more years before Small's manual (1933) can be brought up to date. A knowledge of Latin and Greek derivations may be misleading, for example, P. palustris for longleaf pine, a tree which never grows in swamps. Dr. Bakshi did not mention the necessity of citing the authority for scientific names as P. australis Michx. f., unless it is stated that a certain manual is followed.
According to Fernald (1950) the only common name of Q. laevis Walt. is turkey oak which has also been called Q. catesbae Michx. It is true that Small (1933) applied the name "turkey oak" to Q. cinerea Michx., as well as to Q. laevis. It is not until one reads the last sentence of Dr. Bakshi's paper that the crux of the matter is mentioned, "The Botanical Society of America should set up a commit-tee to find ways and means of encouraging the wider use of scientific names, and to prepare a standard dictionary to fill the gap between the literature published so far and the scientist." (italics mine)
ALBERT M. LAESSLE
University of Florida
1950—Fernald, M. L. Gray's Manual of Botany (8th Edition) pp. 1632.
1958—Laessle, A. M. The origin and successful relationship of sandhill vegetation and sand-pine scrub. Ecol. Monog., 28: 361-387.
1933—Small, J. K. Manual of the southeastern flora. Pub. by author, N. Y., PP. 1545.
1949—U.S.D.A. Trees. The yearbook of agriculture. Government Printing Office, Wash., D. C., pp. 944.
1951—Willis, J. C. A dictionary of flowering plants and ferns. The University Press, Cambridge, England, pp. 752.
Perhaps Dr. Bakshi, in his "A plea for a wider usage of scientific plant names (Plant Science Bulletin, March, 1959), has overlooked some of the reasons why common name usage persists. Let me, right off, declare my support of the usage of Latin binomials in scientific communication. As an associate editor of the Journal of Forestry (not primarily a scientific journal), I make it a policy to leave no common name untranslated in the manuscripts I review.
May I advance some views concerning "scientific names" as an aspect of language? The Latin binomial or trinomial is a group of words we expect to do two things. First, we expect it to designate a species or subspecies, so that we can talk or write about this entity. Secondly, some of us expect this group of words to show the relationship of this entity to other entities. These are reasonable expectations, but are they entirely compatible?
Stability is often advanced as one of the virtues of "scientific names." To be sure, stability in the meaning of symbols enhances their usefulness as units in communication. But do we really want stability in our Latin binomials in their role of indicating relationships? Stability here would mean suspending research, both in library and field. Users of plant names may be annoyed at frequent and often cyclical changes in epithets, but we grudgingly recognize that these signal advances in knowledge and understanding. Foresters, whom Dr. Bakshi singles out for honorable mention, are often struck by the irony of a single tree's outliving a long line (or large circle) of "scientific names." They sometimes solve this difficulty, not with complete success, by the use of common names.
The precision of "scientific names" is often illusory. It is limited by ambiguity (does Corydalis refer to a plant or an insect?), instability, or just plain ignorance concerning the plants designated (unrecognized hybrid swarms, for example). Moreover, as commonly used, without author citations, Latin binomials are not quite as unambiguous as they appear. As things stand at present, "northern red oak" is no less precise than the currently fashionable Quercus epithet (some hold that rubra L. is proper), and is, at least, almost a necessary accessory to the "scientific name."
The lack of precision of the usual Latin binomials has been explicitly recognized in the rules for the nomenclature of cultivated plants, which prohibit the use of Latin names to designate cultivars.
One may be permitted some mental reservations about stability as applied to living things. Language, too, is a living thing. It has a way of resisting codification. Lexicographers recognize this by their practice of recording usage rather than prescribing what is "correct." The stable languages are no longer spoken or written, and few can read them.
Language has uses other than in communication. Scientists, as scientists, properly shun these. Nevertheless, scientists have been known to doff not only their white coats, but their attitudes toward language; they can enjoy the color
of common names, not only in Shakespeare, but in current speech.
Many of us who think of ourselves as scientists may not wish to draw the sharp line between scientist and "common man" implicit in Dr. Bakshi's suggestions. If, as he implies, North Americans are the worst offenders in their neglect of scientific names, I like to think that this is partly because we are not particularly class-conscious. Some of us so convinced of the value of a scientific approach to all human problems that we would not wish to mark off any territory as off limits to the "common man." Admittedly, this thought has been expressed more gracefully in Latin: "Nihil humani a me alienum puto."
Let us, by all means, use Latin binomials consistently and fully in scientific communication. We have much improvement to make in this respect, as Dr. Bakshi points out. I hope, nevertheless, we can avoid propagating a scientific "elite" talking to itself in a private language.
JOHN W. DUFFIELD
Industrial Forestry Association Nisqually, Washington.
Within the past two years Longwood Gardens, Kennett Square, Pennsylvania, has added to or expanded its collections of outstanding ornamental plants of the world for public display. Among these plant groups now on display for the benefit of public enjoyment and education are:
a. Tropical ornamentals, particularly from the Asiatic,
American and African tropics;
b. Cacti and succulents from southwestern United States, the Mediterranean area, South Africa and South America;
c. Economic plants of the tropics and sub-tropics, particularly those items of ornamental and curiosity value;
d. Camellias, particularly hardy types from northern Japan;
e. Tropical water-lilies, including the outstanding species and hybrids as well as other ecologically associated aquatics;
f. An ever increasing number of the finest tropical flowering trees, now under experimental test and evaluation, which we hope to have available for disdisplay in the conservatories through the coming years.
Two new conservatories have been added to the public display facilities as well as a series of thirteen tropical waterlily pools supplied with heated water.
A new experimental greenhouse section consists of ample work area, four 25 x 6o feet greenhouses, one of which will be completely air-conditioned, and laboratory facilities which will serve as a center of experimental research and new plant testing for the purpose of improving Longwood's horticultural displays.
R. J. SEIBERT, Director
Longwood Gardens NEWS AND NOTES
F. R. Fosberg of the Pacific Vegetation Project, National Re-search Council attended the annual meeting of the Unesco Advisory Committee on Scientific Research in the Humid Tropics held at Abidjan, Ivory Coast, Africa, Oct. 16-19, 1959. The meeting was held at the Institut d'enseignment et de recherches tropicales. The meeting was followed be a symposium on "Vegetation in relation to the soil in the plains and lower mountain regions of the equatorial and sub-equatorial zones, and in the adjoining tropical areas", organized jointly by Unesco and the Commission for Technical Cooperation in Africa South of the Sahara.
George W. Burns, Professor of Botany, has been appointed Vice President and Dean at Ohio Wesleyan University. Dr. Burns was Acting President of the University last year. During the past summer he spent two months as botanist attached to the American Geographical Society's studies of glaciers in Alaska.
Also at Ohio Wesleyan University, M. Joseph Klingensmith has been appointed Visiting Assistant Professor of Botany and Bacteriology during the absence of Elwood B. Shining. Dr. Shining is spending the year at the University of Wisconsin pursuing his research on lysogeny of Streptornyces. Dr. Robert W. Long is now Acting Chairman of the Department. Grants totaling approximately $40,000.00 have been received from the National Science Foundation for microbiological, ecological, and genetic research in the Department.
Sydney S. Greenfield represented the Botanical Society at meetings of the National Commission on Accrediting, and the Council on Cooperation in Teacher Education held in Washington, D. C., October 22-25, 1959. He is also the author of the chapter on "Biology" in the new book, "The Case for Basic Education", a program of aims for public schools, edited by J. D. Koerner, Council for Basic Education. The book has been published by Atlantic—Little Brown and Company.
Three colleges, West Virginia Institute of Technology, West Virginia State College, and Morris Harvey College sponsor a regional science fair for junior and senior high schools. Two finalists are selected each spring and are sent to the National Science Fair, where last spring, May 1959, they won second place. Prizes are given at the regional fair for achievements in chemistry, biology, physics, and mathematics in both junior and senior high school groups. Last spring at Morris Harvey College there were 700 entries. The spring 196o fair will be held at West Virginia Institute of Technology.
R. Maurice Myers, Professor and Head of the Department of Biological Sciences at Western Illinois University, will be Tour Director for a Field Tour around the world, sponsored by the University and the National Education Association. The fifty-day tour will include Hawaii, Japan, the Philippines, Hong Kong, Singapore, India, Thailand, Egypt, Greece, Italy, France and Great Britain. The tour will emphasize problems related to health, agriculture, and education, and members may earn college credits.
Samuel P. Johnson joined the Biosciences Branch of the Boeing Airplane Company at Seattle, Washington, in August. Dr. Johnson was formerly at Texas A & M College in the Department of Plant Physiology and Pathology.
News from the Department of Botany and Plant Pathology of The Ohio State University:
Bernard S. Meyer attended, as a member, meetings of the National Science Foundation Panel on Special Projects in Science Education in Washington, D. C., April 17-18 and June 2-3.
Everett S. Beneke of Michigan State University and Arthur G. McQuate of Heidelberg College were Visiting Professors in the Department last summer. Both taught at Stone Laboratory.
C. Wayne Ellett served as Consultant to the Special Projects in Science Education Section of the Division of Scientific Personnel and Education, National Science Foundation, June 15-August 15.
William F. Millington has resigned from the Department of Botany at the University of Wisconsin to take a position in the Department of Biology at Marquette University.
Norman H. Boke of the Department of Plant Sciences, University of Oklahoma, will be on sabbatical leave from February 1960 to February 1961. He will spend from three to four months in the field in Mexico, beginning in February, collecting and photographing cacti for a research project sponsored by the National Science Foundation. The object of the investigation is to provide further knowledge of the development and internal structure of certain cacti and to utilize this in interpreting generic limits and the relationships of the genera.
Anna M. Kummer has been appointed Professor at the Sabin Branch of Chicago Teachers College.
O. J. Eigsti has been promoted to the rank of Professor in the Chicago Teachers College.
ASSISTANTS' SALARIES 1958-59
A survey has been made of what bacteriology teaching and research assistants were being paid at 34 colleges and universities during the year 1958-59. Probably assistants in botany were paid at the same rates.
For teaching assistants the number of hours of work per week ranges from 8 to 22 with most places requiring 15 to 20. Just half of the institutions use teaching assistants for 9 months. About half of the remainder have ro months appointments, the rest 12 months. There is great variation in the number of hours of graduate work that assistants are allowed to carry, but an estimate would be that two courses through the year is what the figures mean. Fifteen institutions charge teaching assistants no fees. In the others, particularly those with charges for out-of-state students, fees may run as high as $400 for the academic year (and these institutions do not necessarily have the highest stipends for teaching assistants).
For Research Assistants the number of hours of work required per week is about the same as for teaching assist-ants, 15-20, with a few institutions allowing up to 40 hours a week, usually with the stipulation that fewer courses may be taken. The arrangements for fees seem to be about the same for both types of assistants.
The stipends for Teaching Assistantships for 9 months run from under $r000 (2 institutions) to just over $2000 (i institution). Three institutions pay between $1300 and $1399, I between $1400 and $1499, 3 between $1500 and $1599, 4 between $1600 and $1699, 2 between $1700 and $1799, 3 between $1800 and $1899 and one between $1900 and $1999. The pay for so months assistantships is about the same and also for 12 months assistantships, although the lowest figure here is between $1200 and $1299 and the highest between $1900 and $1999. It looks as if the 9 months assistants fare as well as the 12 months assistants, or better, since they can carry on research, or take another job during the remaining 3 months of the year.
Research Assistants who work for 9 months are paid between $1300 and $1999. The stipends for those who work for Io months range from $1400 to $1899. Those who work for 12 months fare somewhat better but not much. In to institutions they are paid over $2000, the highest $2800, if they work 40 hours a week and take only 6 hours of work for academic credit. If the university has few course requirements for the advance degree student, research assist-ants may get their degrees at higher pay in the same length of time as teaching assistants. Also, they may get to carry on some of their own research while being paid to assist someone in his research. They may be junior authors of research reports. But the teaching assistant has gained valuable teaching experience.
What does it all add up to? It is hard to say, more than that present day teaching and research assistantships pay stipends that seem to be adequate for a single person to live on, so that he should decide to go to whatever college or university offers him the kind of graduate instruction he thinks is what he wants. He would be wise to read the fine print, however, and discover how much he will have to pay in fees from the announced stipend.
HARRIET B. CREIGHTON
The Scholar's Library, Publishers, 1619 First Avenue, New York 28, N. Y. wishes to make known its new plan to publish topical bibliographies in the biological sciences. These bibliographies will be reference lists to the literature of an area of specialization not frequently enough handled in the review journals. It is hoped that the author will circumscribe his subject so that a list of 200-350 entries will be comprehensive. A brief introduction, if the author finds it desirable, will be welcomed. The publications will be re-produced by photolithography from the author's own type-script and saddle stitched with a printed cover and title page. The company would be glad to receive proposals from prospective authors.
Dr. Margaretha G. Mes, Professor of Plant Physiology and Biochemistry at the University of Pretoria, South Africa, died on July 25, 1959.
In honor of the late Professor Mes, the Plant Physiological Research Institute of the University of Pretoria has been renamed the "Margaretha Mes Institute for Plant Physiology and Plant Biochemistry".
The Fourth International Conference on Plant Growth Regulation was held at the Boyce Thompson Institute for Plant Research, Yonkers, New York, August Jo to 14, 1959. The Conference was sponsored jointly by the Institute and by the New York Botanical Garden and the Brooklyn Botanic Garden. The program was coordinated with the IXth International Botanical Congress held at Montreal, Canada, August 19 to 29.
The Conference was attended by 126 invited participants from 17 countries. The first day was devoted to naturally-occurring growth substances, the second to the gibberellins, the third to the synthetic auxins, and the fourth to other plant growth substances. In addition to the scheduled papers, ample time was provided for discussion periods. The papers presented and the discussion remarks will be published in book form by the Iowa State College Press in May, 1960. Copies will be sent to each participant and will be available to others at nominal cost.
Previous International Conferences on Growth Regulants were held at Wye College in 1955, the University of Wisconsin in 1949, and in Paris under the auspices of the League of Nations in 1937. The present Conference was the first one at which the gibberellins were discussed. The Japanese scientists who did the early work on the gibberellins, T. Hayashi, J. Kato, and Yusuke Sumiki, took part in the Conference, as well as P. W. Brian, who first called the attention of the western world to the Japanese work. Evidence showing the probable widespread occurrence of gibberellin-like substances in plants was presented by C. A. West. Others who took part in the program on the gib-
The Division of Biological and Medical Sciences of the National Science Foundation announces that the next closing date for receipt of basic research proposals in the Life Sciences is January 15, 1960. Proposals received prior to that date will be reviewed at the spring meeting of the Foundation's advisory panels and disposition will be made approximately four months following the closing date. Proposals received after the January 15, 1960, closing date will be re-viewed following the summer closing date of May 15, 196o. Inquiries should be addressed to the National Science Foundation, Washington 25, D. C.
Harriet B. Creighton, our former Editor, is on sabbatical leave from Wellesley College until September, 196o. She has a Fulbright Lectureship and will lecture at the University of Cuzco in Peru, on plant genetics. She will also be engaged in research on maize cytogenetics. Dr. Creighton will travel in the Andean countries and visit Research Stations operated by the Rockefeller Foundation. berellins included B. O. Phinney, M. J. Bukovac, S. H. Wittwcr, A. W. Galston, S. Housley, and B. J. Deverall. A paper submitted by M. K. Chailakhyan of the U.S.S.R. on the effect of gibberellic acid on growth and flowering was also read at the Conference.
Among the new discoveries reported at the Conference was the disclosure of a new class of auxins in the long chain aliphatic compounds. i-Docosanol, which is more active than indoleacetic acid, was isolated from Maryland Mammoth tobacco by D. G. Crosby and A. J. Vlitos. They also isolated, from the same source, an active long chain fatty acid not yet fully characterized. Bruce Stowe also presented evidence of growth-promoting activity by long chain aliphatic compounds.
New theories on the structural requirements for growth regulants for reaction with the necessary binding sites, were presented in separate papers by K. V. Thimann and J. van Overbeck. Some physical chemical aspects of synthetic auxins with respect to their mode of action were presented by Virgil Freed.
The isolation of a new acid from coconut milk which gives about half the stimulation of growth of tissue cultures produced by whole milk, was reported by L. H. Weinstein, L. G. Nickell, and W. J. Tulecke.
One of the evenings was devoted to a memorial dinner to the late P. W. Zimmerman who, with his associate, A. E. Hitchcock, first tested 2,4-D for its effect on plant growth and development. Other chemicals first worked with in his laboratory include indolebutryic acid and 1-naphthleneacetic acid as well as a variety of substituted derivatives of benzoic and aryloxyacetic acids. Zimmerman was originally a member of the organizing committee for the Conference but became ill and died while on a business trip in August, 1958 at the age of 74.
The day after the formal sessions ended, the participants were taken on a chartered boat around Manhattan Island. This afforded an opportunity for them to meet members of the botany departments of Columbia and Rutgers Universities and staff members of the sponsoring institutions who are not directly interested in growth substances and there-fore were not participants in the scientific sessions.
Financial support for the Conference was furnished by the Rockefeller Foundation, the National Science Foundation, and 15 industrial companies interested in agricultural chemicals. George L. McNew, Managing Director of the Boyce Thompson Institute, was Chairman of the Organizing Committee for the Conference. A. J. Vlitos, formerly at the Institute and now with Caroni, Ltd. in Trinidad, was Secretary of the Organizing Committee and Chairman of the Program Committee.
LAWRENCE P. MILLER
Boyce Thompson Institute for Plant Research, Inc.
Yonkers, New York