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not for scientific or practical purposes, but
gave source to wild speculations in disease and
the origin of life. However, its useful day
came many years later, when its discoveries
were made use of in many practical problems,
connected with disease of plants and animals
and the physiological problems in connection
with crop production.

PLANT PATHOLOGY

Meyer, an extraordinary man who died at
the age of thirty-six, published a work on
phytopathology, a paper on corn smut and one
on actinomyces. He was a physiologist and
looked at the problem of disease from the
standpoint of physiology, really the only way
Camerarius
the subject should be treated.

seems to have antedated the work of Meyer by
over one hundred years in the publication of
his paper "De Ustilagine Frumenti." Julius
Kuehn was primarily an agriculturist and as
director of the Agricultural Institute at Halle
started a series of experiments on plants that
have become classic. While thus engaged in
the work he became interested in a study of
the diseases of plants. To him we owe the first
comprehensive treatise on plant pathology.
He had breadth of vision to study and inter-
pret what he saw with the microscope and thus
there came into being "Die Krankheiten der
Kulturgewächse," which stands as a monu-
ment to his labors.

It is the only botanical
paper by him listed by Pritzel in his The-
saurus. M. J. Berkley's work, "Introduction
to Cryptogamic Botany," gave to English-
speaking people the first real treatise on plant
diseases, which laid a sure foundation for a
study of plants, along economic lines.

De

All of the work on plant diseases and the
anatomy of plants was better established later
through the classic work of DeBary.
Bary, of course, did not have, except in some
cases, the practical problems in mind, though
the science of botany and plant pathology in
particular have been greatly benefited through
his profound researches in connection with
the development of life history of fungi. De-
Bary brought to the science of mycology a

breadth of knowledge along many lines of bot-
any and one marvels at the enormous amount
of research work he did. Nor should we omit
to mention the great work of Tulasne (who
had the merit of first breaking the ground in
a study of rust, smuts and ergot), on the dis-
covery of the germination of the spores of
rusts, smuts and the sexual organs of Perono-
spora. While these researches did much for
mycology, indirectly they have been of great
practical importance to pathology. Robert
Hartig, perhaps the foremost student in the
world during his lifetime of the diseases of
forest trees and the decomposition of wood,
exerted a great influence on the practise of
forestry, followed later by the splendid work
of Marshall Ward, a student of Hartig. We
may mention in this connection the work of
Fischer de Waldheim, Wolff, Sorauer, Appel,
Millardet, Prillieux, Jones, Halsted, Arthur.
Bolley, Atkinson, Stewart, Whetzel, Freeman
Clinton, Thaxter, Duggar, Stakman, Cook,
Stevens and Melhus. These as well as a
host of others, added to this economic phase
of botany, making secure the science of
plant pathology. I need only add here
plant pathology.
that the stimulus given by these men to
this economic phase of botany has been com
municated to all parts of the world; and
SO we may mention especially the pionee
work by Dr. Farlow on Gymnosporangium
grape vine mildew, onion smut, Dr. Burril
on apple blight and sorghum blight, the epoch
making researches along the line of bacteria
diseases of plants by Dr. Erwin F. Smith
Surely America may well be proud of it
achievements. The present age has hundred
of new problems in plant pathology. Th
superficial only was touched on by the earl
workers. We may mention especially the roo
disease of cereals and other crops. The plan
pathological studies on these parasites ha
changed our methods of agriculture con
pletely. We need more careful and profoun
work on many of the problems worked upo
by the pioneers. The pioneers who blazed th
way may be excused for errors, but the mo
ern investigator should not be. He has th

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POLLINATION OF FLOWERS

Another phase of the subject of economic cany is that of pollination. Progress was

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Geoffroy, who as early as 1711 made me observations on the nature of the style, said to have conducted some experiments th maize; however that may be he did make e of the work of Camerarius. Geoffroy conuded from various sources that fertilization as a kind of fermentation, but he was inined to accept a second view of Morland that e pollen grains contain the embryo which nd their way to the seed. We may also recall Le work of John Logan, at one time govnor of the colony of Pennsylvania, who onducted experiments on the fertilization of aize, in which he noted that cobs covered ith muslin did not produce seed, but seed as formed on cobs where pollen came in conact with the stigmas. Logan suggested that he wind carried the pollen. Gleditsch in a tudy of one of the palms (Chamarops umulis) strewed loose dried pollen on the tigmas of a female plant which produced seed which later was planted and germinated; a imple experiment but a convincing one to the -otanists of the time, who had never seen polination demonstrated before. Philip Miller n 1751 calls attention for the first time to the mportance of insects in the pollination of ulips. The first scientific experiments on hyprids were made by Koelreuter, who discovered the use of nectar and the importance of insects in the pollination of flowers. Koelreuter clearly set forth the facts that the mingling of two substances produced a seed. These general statements as set forth by him still hold true. He was a skillful experimenter in the hybridizing of plants. The work of Sprengel on the pollination of flowers is well known to the older botanists. His sharp discriminating observations on the relation of insects to flowers were little understood at the time. The full import of these problems were recognized by Charles Darwin, who in his masterly way showed the application of this

in practical problems. Earlier Sir Andrew Knight had demonstrated "that no plant fertilizes itself through an unlimited number of generations." Dr. Gray put this in a much more terse way. A score of investigators like Hermann Mueller, Fritz Mueller, Delpino, Ludwig Axell, Hilderbrandt and in our country men like Gray, Trelease, Riley, Foerste, Beal and Robertson demonstrated the use of insects in pollination and the application of this fact to important agricultural crops. These fundamental facts are fully recognized to-day in the growing of apples, alfalfa, sweet clover, melons, squash and cucumbers. The orchardist recognizes the importance of bees in connection with the growing of apples, pears and plums. The farmer recognizes the importance of bees in the alfalfa and sweet clover fields, just as Charles Darwin recognizes that the bumble bee is important in the red clover pollination. In this connection, as an economic problem, I may call attention to the honey flow in flowers. It is true beekeeping is only one of our minor agricultural problems dependent entirely on the relative abundance of honey plants in a given region. There are a great many interesting physiological problems in connection with nectar secretion, as Kenoyer has shown. One wonders why alsike clover scarcely yields any nectar for bees in Iowa and yet in some regions of the country it is one of the best of nectar plants. There is seldom any nectar in buckwheat flowers after 10:00 A.M. in Iowa, and yet in sections of the United States the period of nectar flow is much longer. Is soil alone a factor or is moisture an important factor, or are the two factors combined? We have enormous expanses of waste land along our highways in the United States, why not combine the esthetic with the economic if we can find plants that are suited for such places that will yield good returns for the beekeeper.

PLANT BREEDING

I heard a practical fruit grower in Iowa say the other day when a new chance seedling apple was shown me that nearly all of the new good things in the fruit line are chances; that

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is to say the new productions by Burbank,
Hansen, Patten, Beach, Hedrick, Webber and
many other plant breeders are not equal to
those found in nature. I need only recall
the many fine things the modern plant breeder
has produced. Of course, new types will al-
ways appear, as they have in the past. The
to me, will
work accomplished, it seems
justify larger expenditure of money.

In the matter of fundamental study of these problems practical agriculture, horticulture and floriculture are indebted to the classic fundamental work of Hoffmeister and Strasburger. This work led up to and explains the physical basis of Mendelism discovered by Gregor Mendel, a work that is most important in the breeding of new types. We have had a host of botanical investigators who have enhanced our knowledge of plant breeding, linking it with practical work like Nilsson, Johannsen, Bateson, Correns, Shull, White, Webber and Emerson. Agriculture and horticulture are indebted to the epochmaking work of DeVries on mutation. His work has set a score of botanists to work on the pedigree culture work. I may mention Nilsson, Johannsen and Gates especially. Possibly the outstanding problem of the pomologist in states like Iowa and Minnesota is that of hardiness. In breeding experiments at the present time it is necessary to set the trees out and test them for a term of years, to see whether or not this climate is too severe. Bakke in some recent experiments has found that by ascertaining the depression of the freezing and the moisture content at a time when all the tissues are in an active state of growth, it is possible to obtain an idea of the comparative hardiness of different apple trees. These tests have been made upon trees in the nursery as well as upon trees in an orchard, 10 years old, with practically the same results.

SEED STUDIES

After a consideration of pollination the The first matter of seed is of importance. great work published is that of Gartner, "De fructibus Seminibus plantarum." Gartner was free from the bias of those who preceded him.

We have a truly modern work by one whom we may regard as a modern man of science. He made a comparative study, correctly determined the relation of the endosperm to the cotyledon and named the embryo. We have had a long line of investigators on the subject of seeds.

The practical application found expression in the work of Nobbe, Harz and others. We may recall the work of Nobbe in the testing of seeds at the small experiment station at Tharand, which was the beginning of the experiment stations such as we know them today. Nobbe did not merely do the mechanical part in connection with the testing of seed but inquired into real scientific problems in connection with specific gravity, and the vital ity of seeds under different conditions o storing. The germination of many seeds is of special concern to the agriculturist, be cause it is important to know under wha conditions a seed will germinate best to bring the largest returns. It is a matter also o some concern for the farmer to know whethe weeds' seeds have a varying period of vitalit when buried in the soil, whether for instanc the seeds of Hibiscus Trionum and Abutilo Theophrasti will come up in his fields after quarter or half a century when he practise rotation of crops. The vitality and structur of seeds has of course received much atten tion. I need only recall the classic work c DeCandolle who more than a century ag studied the prolonged vitality of seeds. Th data secured by DeCandolle is frequentl quoted in text-books of plant physiolog. Also much later work of Becquerel, Bea Ewart and Hanlein on delayed germination as well as the work of Crocker and his st dents like Shull, on the delayed germination seeds, like wild oats and other seeds of ec nomic importance. To Crocker we are in debted for an explanation of the delaye germination of such seeds as the cocklebu Knowing that there is a delay in some se the farmer is better able to follow a ration practise in the treatment of seeds. I am su that most of you are familiar with the wo of Schleiden and Vogel, Chalon, Malpig

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aberlandt, Sempolwski, Beck, Moeller and esterle, Mattirolo and Buscalioni, Hanausek, arz, Junowicz and many others who were terested in a study of seeds of Leguminosa, articularly with reference to the light line. The writer more than a quarter of a century go brought the literature on this subject toether in his paper on the Comparative natomy of Seeds of Leguminosa." Comaratively little has been done since. Inensive studies on the seeds of such families s the Leguminosa. Convolvulaceæ, Cucurbiacer, Malvaceae, Tiliacea should be made beause in most of these families where the ight line occurs the seeds have a prolonged itality. The subject has more or less of a practical bearing. The problem as to the nature of the light line in these seeds has not been solved. A number of present-day botansts, like Martin, Harrington and others are aking up the problem. Present-day investigations with seeds are bringing many valuable practical results in commercial seed production, as in clovers. The seed control work by the establishing standards of purity is a practical problem. The work in determining the conditions of germination, experiments with light, electricity, heat, moisture and drying and studies of seed coat are also important. The important problem of rate of maturing of seed in storage is being worked out. Seedtesting laboratories, while they are obliged to answer the immediate pressing problems on the impurities of seeds and their germination are engaged in a study of the more fundamental problems of the viability of seeds. It has been the custom for the American Seed Analysts Association to send to its co-workers seeds to test for purity and vitality. With careful treatment, there is still the greatest variation in the results. Presumably, in part at least, the methods used by seed testers is not the same and, therefore, the result can not be uniform. We should bear in mind that the viability is a matter of climate and condition of storage of the seed. The fundamental problems of every one of the great staple agricultural crops, so far as vitality of

seeds is concerned, has not been entirely solved and awaits solution by the investigator.

The writer and Miss King, during the past few years, have continued investigations on germination of seeds of forest trees and shrubs. The results exhibit surprising irregularity and uncertainty in the germination of these seeds. Boerker, of Nebraska, has followed the same line of research. The work of Sir John Lubbock on Seeds and Seedlings and various papers of Tubeuf on seeds of forest trees, although purely morphological are always valuable for reference and bear in general upon forestry problems, of economic botany.

GRASSES

Botanists have long recognized the importance of grasses in our welfare. The prosperity of the United States outside of the rich natural resources of forestry, mines and water power is concerned with the economic production of cereals, cotton and livestock. Turning to some of the older works I recall the work of Sowerby and Parnell on grasses, Metzgar, "Die Gereidarten," Stebler and Schroeter, "Körnicke, Die Gebreidearten," and Hackel, "True Grasses." In our own country early works were Flint's "Grasses of Massachusetts," Klippart, "Grasses of Tennessee," Lapham, "Grasses of Wisconsin," Vasey, "Grasses of the United States," Lamson-Scribner, various papers published by the U. S. Department of Agriculture, Beal, "Grasses of North America," Hitchcock and Chase papers. These and other authors touching the economic problems of cereals, like Hunt, Carleton, Shear, Warburton and Ball have stimulated prduction but it would seem as though we have only scratched the surface so far as a study of the real problem of cereal production is concerned. It vitally concerns us as a nation to stimulate the production of cereals and forage crops because the ever-increasing population demands increased production. How can the botanists contribute more to the welfare of mankind than to study such problems as the physiology of the nutrition of the growing of wheat, maize, oats, barley and rice, or to make a study of pollination

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SCIENCE

a

are

under different climatic conditions, or the
breeding of varieties of cereals resistant to
diseases? We might well consider the stu-
pendous losses from parasitic fungi of cereals.
There never was a time when research on
cereals and other agricultural crops was as
important as it is to-day. We have, on
large scale, undertaken the removal of the
barberry in the wheat-growing section of the
country, because the plant pathologists are
convinced that the common barberry is an im-
portant factor in rust production. And yet,
I was confronted with the frequent statement
by practical men in western Minnesota that
there is no barberry in this particular section.
I certainly saw none in the immediate area
to speak of, although there was some bar-
berry thirty miles to the south. I could
not make the questioner see the importance
of the barberry in connection with grain
doubt there
no
Some seasons
rust.
on grasses.
actually viable uredo
The point, I think, we should determine
to convince the wheat grower on is this:
are the uredo spores viable in weedy grasses,
the uredo
spores be
and how far
carried? The farmer who loses $3,000 on a
quarter section of land in a single year of
wheat-growing wants some solution of the
problem. It is the duty of the government
and the botanist to solve the problem for the
country. Unless this is done by extermina-
ting the barberry, the breeding of resistant
varieties and the elimination of weedy grasses,
the growing of spring hard wheats will be a
thing of the past, and the farmer will be
forced to turn his attention to the growing of
other cereals, not subject to rust. The gov-
ernment and the states directly interested, can
well afford to spend a half million dollars an-
nually until the problem is solved.

can

WEEDS

spores

The subject of weeds is related to that of plant disease. It greatly interests the farmer and gardener. The farmers of the United States, at least in some sections, have endeavored to remove by legislation some of the injurious weeds, expecting, of course, that the

law would be obeyed and the weeds would so
be eliminated, but instead they are constan
increasing. As illustrations of weed legis
tion I need only remind you that some twen
five years ago nearly all the northweste
states made it illegal to permit Russian this
to grow. During these twenty-five years
has spread from the Atlantic to the Paci
In Washington and Colorado where the con
tions are suitable it covers the ground
little travelled roads and on the plains.
Iowa we made an effort by legislation to
duce the infested areas of quack grass,
it has so increased that the farm values
some cases are reduced because of its presen
During the past two seasons I have recei
a large number of specimens of knapw
(Centaurea solstitialis) from many points
Iowa and northern Missouri, distribu
largely through alfalfa seed. Buckhorn (Pl
tago lanceolata) is rapidly interfering w
clover culture in Iowa.

We have described weeds and how
eradicate them, because this is the kind of
formation the farmer wants, but we have
solved a single one of the important proble
in connection with weeds. Weeds have an
portant bearing on the crops produced.
small ragweed no doubt reduces the efficie
of the Iowa pasture during the autu
months fully one half, the weeds of corn fi
frequently cut the yield one third. How th
yields are reduced has not been determin
How much do we know about the mechan
interference of weed roots and the agri
tural crop? So far as I know, there is
solutely no data on the subject. Water
an important factor in crop production; th
fore, a study of transpiration is of importa
in connection with a study of weeds. It
been pointed out by Livingston that tra
piration is practically a simple function
the leaf surface and that the total transp
tion is a measure of the growth of a pl
whether it is one growing in a waste place
of economic importance.

Kesselback makes it clear that weeds suc sunflower use more than three times as m water per plant as corn. while water used

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