Chapter C: E. Dutton, Critical observations on theories of the earth’s (10)

The first such American school was established by Louis Agassiz at the island of Penikese on the coast of Massachusetts in 1873, succeeding his private laboratory at Nahant. During that Summer more than forty students gained enthusiasm for the work of future years. Unfortunately the laboratory so auspiciously started was of brief duration, for the death of Agassiz occurred in December of the same year, and the laboratory was discontinued at the end of the following Summer. Shortly afterward Alexander Agassiz equipped a small private laboratory at Newport, Rhode Island, and W. K. Brooks established the Chesapeake Bay Zoological Laboratory.

At this time the United States Fish Commission was engaged under the direction of Spencer F. Baird in a survey of the marine life of the waters off the Eastern Coast. Between 1881 and 1886 the Commission established the splendidly equipped biological station at Woods Hole, Massachusetts. Both here and at the Fish Commission Laboratory at Beaufort, North Carolina, much work in general zoology as well as in economic problems is accomplished. These laboratories are designed particularly for specialists engaged in researches connected with the work of the Fish Commission.

A need was soon felt for a marine laboratory along broader lines, and one available to the students and teachers of the schools and colleges. To meet these requirements the Woods Hole Marine Biological Laboratory was started in 1887, as the successor to an earlier laboratory at Annisquam, and has since become a great Summer congress for biologists from all parts of the country. It is safe to say that no other institution has been of equal service in securing for biology the high plane it now occupies in American science. The leading spirit in the establishment of this laboratory and its director for many years was Charles O. Whitman.

Successful marine laboratories are located also at Cold Spring Harbor, Long Island; at Harpswell, Maine; and at Bermuda. The Carnegie Institution maintains a laboratory at Tortugas Island, Florida, for the investigation of tropical marine life.

On the Pacific Coast marine laboratories are located at Pacific Grove and at La Jolla, California, and at Friday Harbor, Washington. Several other biological laboratories are open each Summer on our coasts, as well as a number of fresh-water laboratories on the interior lakes. There are also several mountain laboratories. The influence of these laboratories on American biology is immeasurable.

_Natural History Museums._

Museums of Natural History or “Cabinets of Natural Curios” as they were sometimes called, were established in the first half of the nineteenth century in connection with the various natural history societies. These were of much service in stimulating the collection of zoological “specimens” and in arousing a popular interest in natural history.

The zoological museum of earlier days consisted of rows on rows of systematically arranged specimens, each carefully labelled with scientific name, locality, date of collection and donor—much like the pages of a catalogue. All this has now been changed; the bottles of specimens have been relegated to the storeroom, and the great plate glass cases of the modern museum represent individual studies in the various fields of modern zoological research, or individual chapters in the latest biological text-books. Often the talent of the artist and the skill of the taxidermist are cunningly combined to produce most realistic bits of nature.

The United States National Museum, the American Museum of Natural History, the Field Columbian Museum and the Museum of Comparative Zoology are among the finest museums of the world, while many of the states, cities, and universities maintain public museums as a part of their educational systems.

_Systematic Zoology and Taxonomy._

The work in systematic zoology is now mainly carried on by specialists in relatively small groups of animals. This is necessitated both by the increasingly large number of species known to science and by the completeness and exactness with which species must now be defined. The majority of systematic workers are now connected with museums where the large collections furnish material for comparative studies.

Prominent in this field is the United States National Museum, the publications of which are mainly taxonomic and zoogeographic, and cover every group of organism. The adequacy of this great museum for such studies may be illustrated by the collection of mammals. This museum has the types of 1135 of the 2138 forms (including species and subspecies) of North American mammals recognized in Miller’s list,[175] and less than 200 forms lack representatives among the 120,000 specimens of mammals. Systematic monographs of several of the orders of mammals have been published.

Systematic study of the birds has brought the number of species and subspecies known to inhabit North and Middle America to above 3000. The most comprehensive systematic treatise is the still incomplete report of Ridgeway[176] of which seven large volumes have already been issued.

On the reptiles, the most complete monograph is that by Cope[177] entitled “The Crocodilians, Lizards and Snakes of North America.”

The Amphibia have also been studied by Cope, whose report on the Batrachia of North America[178] is the standard taxonomic work.

The most comprehensive systematic work on fishes is the “Descriptive Catalogue of the Fishes of North and Middle America” by Jordan and Evermann.[179]

The invertebrate groups have been in part similarly monographed by the members of the U. S. National Museum staff and others, and further studies are in progress. Other taxonomic monographs published by this museum include the various groups of animals from many different parts of the world.

A number of the larger State, municipal, and university museums publish bulletins on special groups represented in their collections as well as articles of general zoological interest.

Expeditions, subsidized by museum and private funds, are from time to time sent to various parts of the world and their results are often published in sumptuous manner.

The total number of living species of animals is unknown, but considering that about a quarter of a million new species have been described during the past thirty years, it is probable that several million species are in existence to-day. More than half a million have been described. These are probably but a small fraction of the number that have existed in past geological ages.

Thus, in spite of all the work that has been done in systematic zoology and as the number of known species continues to increase, there still remain many groups of animals, some of which are by no means rare or minute, in which probably only a small proportion of the species are as yet capable of identification.

It is only since the publication of Ward and Whipple’s “Fresh-water Biology” within the past year that the amateur zoologist could hope to find even the names of all the organisms which may be collected from a single pool of water. And in many cases he will still meet with disappointment, for many of our protozoa and other fresh-water organisms have not yet been described as species.

During the past few years there has been a tendency on the part of some of our biologists engaged in experimental work to disparage the studies of the systematists. It must be granted, however, that both lines of work are essential to the sound development of zoological science, for experimental investigations in which the accurate diagnosis of species is ignored always result in confusion.

_Ecology._—The marvelous modifications in structure and instincts by which the various animals are adapted to their surroundings now forms a special topic in biological research and one of the most fascinating. The adaptations in habitat, time, behavior, appearance and even in structure are found capable of a certain individual modification when studied experimentally.

_Zoogeography._—Closely associated with systematic zoology, and indeed a part of the subject in its broader sense, is the study of the geographical distribution of animal species and larger groups.

_Paleontology._—The geological succession of organisms embraces a field where zoologist and geologist meet. The wonderful progress made by American investigators is well described in the preceding chapters on Historical Geology and Vertebrate Paleontology.

_Biometry._

Since Darwin’s theory of evolution postulated the origin of new species by means of natural selection, it was obviously necessary in order to apply a critical test to determine the precise limits of a species. It was, therefore, proposed to subject a given species to a strict examination by the application of statistical methods to determine the range of variation of its members and the extent to which the species intergrades with others. Other problems, particularly those concerning heredity, were treated in similar manner. This branch of biological science was particularly developed by the English School, led by Sir Francis Galton, followed by Karl Pearson and William Bateson.

In America the methods of biometry have been utilized extensively by Charles B. Davenport, Raymond Pearl, H. S. Jennings and others in the solution of problems in genetics and evolution. Their work shows the great value of critical statistical analysis in the interpretation of biological data. A thorough training in mathematics is now found to be hardly less important for the biologist than is a knowledge of physics and chemistry, for the science of biometry has become one of the most important adjuncts to the study of genetics.

_Comparative Anatomy and Embryology._

_Comparative Anatomy._—Upon the foundations laid down by Cuvier a century ago the present elaborate structure of comparative anatomy of animals, both vertebrate and invertebrate, has been developed. Vast as is the present accumulation of facts and theories many important problems still await their solution. Jeffries Wyman was long a leader in this field, where many workers are now engaged.

_Embryology._—The embryological studies, so brilliantly begun by Von Baer early in the nineteenth century, are still in progress. They have now been extended to the groups more difficult of investigation and into the earliest stages of fertilization and implantation in the mammals. Artificial cultural methods have yielded important results. Louis and Alexander Agassiz, Mark, Minot, Brooks, Whitman, Conklin and E. B. Wilson have taken prominent parts in this work.

In the early nineties embryological studies were directed to the arrangement of cells in the dividing egg, and there was much discussion of “cell lineage” in development. Valuable as were these studies they threw comparatively little light on the general problems of evolution.

_Experimental Embryology._—A more fertile field, developed at the same period and a little later, was found in experimental embryology. The discoveries made by Driesch and others in shaking apart the cells of the dividing egg or by destroying one or more of these cells gave a new insight into the potency of cells for compensatory and regenerative processes. These studies attracted many able investigators, who made still further advance by subjecting the germ cells, developing eggs, embryos, and developing organs to a great variety of artificial conditions.

_Artificial Parthenogenesis._—Another question concerns the nature of the process of fertilization and the agencies which cause the fertilized egg to develop into an embryo. In 1899 Jacques Loeb succeeded in causing development in unfertilized sea-urchin eggs by subjecting them to concentrated sea water for a period and then returning them to their normal environment. To this promising field of experimental work came many of the foremost biologists both in America and Europe. It was soon found that the eggs of most groups of animals except the higher vertebrates could be made to develop into more or less perfect embryos and larval forms by treatment with a great variety of chemical substances, by increased temperature, by mechanical stimuli and by other means. This artificial parthenogenesis, as it is called, has also been successful in plants (_Fucus_), and recently Loeb has reared several frogs to sexual maturity by merely puncturing with a sharp needle the eggs from which they were derived. Loeb, then, maintains that “the egg is the future embryo and animal; and that the spermatozoon, aside from its activating effect, only transmits Mendelian characters to the egg.”[180]

Further experimental analyses of the nature of the fertilization mechanism have recently been made by Morgan, Conklin, F. R. Lillie, and others.

_Germinal Localization._—The question as to whether the egg contains localized organ-forming substances has been studied experimentally particularly by means of the centrifuge. The results indicate that neither of the older opposing theories of “performation” or “epigenesis” is applicable to all eggs, but that in certain organisms the eggs possess a well marked differentiation while in others each part of the egg is essentially, although probably not absolutely, equipotential.

_The Germplasm Cycle._—Since Weismann’s postulation of the independence of soma and germplasm in 1885 many attempts have been made to trace the path of the hereditary substance from one generation to the next. A recent book by Hegner[181] summarizes the success attained in various groups of animals.

_Cytology._

Another important field of investigation which has attracted many workers is that which pertains to the life of the cell—the science of cytology. Although the celltheory was established as early as 1839, little advance was made in this subject in America before 1880. Since that time, however, Americans have been so successful in cytological discoveries that they are now among the world’s leaders in this field.

These studies have been followed along both descriptive and experimental lines. The most prominent of the early workers in this field are E. L. Mark and E. B. Wilson. Mark’s description of the maturation, fecundation, and segmentation of the egg is the most accurate and complete of the early cytological studies. Wilson’s discoveries concerning the details of fertilization and his “Atlas of Fertilization and Karyokinesis,” published in 1895, have now become classic. Wilson, too, has published the only American text-book on cytology,[182] and has more recently taken the lead in studies concerning the relation between the chromosomes and sex. Besides Wilson, Montgomery, Mark, McClung, Morgan, Miss Stevens, Conklin and their associates and students have now furnished conclusive evidence that the sex of an organism is determined by, or associated with, the nuclear constitution of the fertilized egg. This constitution is moreover shown to be dependent upon the chromosomes received from the germ cells.

This explanation is in strict accordance with the results of experimental breeding. It is also quite in harmony with the Mendelian law of inheritance, and in fact forms one of the strongest supports for the view that all Mendelian factors are resident in the chromosomes. Recent work has also discovered the mechanism which governs the complicated conditions of sex which occur in those animals which exhibit alternating sexual and parthenogenetic generations. These remarkable processes are in all cases found to depend upon a definite distribution of the chromosomes.

Other recent experimental work has shown that while the sex is thus normally determined in the fertilized egg, it is in some animals not irrevocably fixed, and the normal effect of the sex chromosomes may be inhibited by abnormal conditions in the developing embryo, as is demonstrated by the recent work of Lillie and others.

The cytological basis for Mendelian inheritance has been very extensively studied by Morgan and his pupils in connection with their work on inheritance in the common fruit fly _Drosophila_. The evidence supports Weismann’s earlier hypothesis that the chromosomes are the bearers of the heritable factors, and that these are arranged in a series in the different chromosomes. This theory is shown to be in such strict accord with both the cytological studies and the results of experimental breeding that Morgan has ventured to indicate definite points in particular chromosomes as the loci of definite heritable factors, or genes.

Confirmation of this view is furnished by the behavior of the so-called sex-linked characters, the genes for which are situated in the same chromosome as that which carries the sex factor. Many ingenious breeding experiments indicate further that all the hereditary characters in _Drosophila_ are borne in four great linkage groups corresponding with the four pairs of chromosomes which the cells of this fly possess.

_Comparative Physiology._

None of the experimental fields has been of greater importance in zoological progress than that which concerns the functions of the various organs. Without this companion science morphology and comparative anatomy would have become unintelligible. American investigators, among whom G. H. Parker stands prominent, have taken a leading part in this field also.

_Neurology._—The physiological analysis of the components of the nervous system, both in vertebrates and invertebrates, is another important branch of experimental biology. The 28 volumes of the Journal of Comparative Neurology attest the large influence that American investigators have had in the development of this science.

_Regeneration._—Experimental studies on the powers of regeneration in plants and animals have been made from the earliest times. During the past few years, however, there has been made a concerted attempt to analyze the factors which determine the amount and rate of regeneration. Much progress has been made toward the postulation of definite laws applicable to the regenerative processes of the parts of each organism. The critical analyses of Morgan, Loeb and Child have been particularly stimulating.

_Tissue Culture._—Another line of experimental work which has been developed within the past few years by Harrison, Carrell, and others is the culture of body tissues in artificial media. These experiments have included the cultivation in tubes or on glass slides of the various tissues of numerous species of animals. They have yielded much information regarding the structure, growth and multiplication of cells, the formation of tissues, and the healing of wounds.

_Transplantation and Grafting._—Closely associated experiments consist in the transplantation of organs or other portions of the body to abnormal positions, to the bodies of other animals of the same species or of other species. In this way much has been learned about the potentiality of organs for self-differentiation, for regulation, for regeneration and for compensatory adaptations. The experiments have shown, further, the independence of soma and germplasm and have revealed the nature of certain organs whose functions were previously obscure.

_Tropisms and Instincts._—Another field of experimental biology concerns the analysis of behavior of organisms in response to various forms of stimuli. These studies are being prosecuted on all groups of organisms, including the larval stages of many animals, and are yielding most remarkable results. The success in this field of research is largely due to stimulating influence of Jacques Loeb, Parker, Jennings, and their co-workers.

_Biological Chemistry._—Still another experimental field which has developed into one of the most important of the biological sciences relates to the fundamental chemical and physical changes which underlie all organic phenomena. A knowledge of both physiological and physical chemistry is to-day essential for all advanced biological work. The peculiar nature of life itself, of growth, disease, old-age, degeneration, death and dissolution are presumably only manifestations of chemical and physical laws. The ultimate goal of all experimental biology, therefore, will be reached only when the basic physico-chemical properties of life are understood. At that time only will the perennial controversy between vitalism and mechanism be ended.

_Economic Zoology._

A moment’s reflection will show that economic biology is the most essential of all sciences to the human welfare and progress. For man’s relation to his environment is such that the penalty for ignorance or neglect of the biological principles involved in the struggle for existence quickly overwhelms him with a horde of parasites or other enemies.

It is only by the intelligent application of biological knowledge that our food supplies, our forests, our domesticated animals and our bodies can be protected from the ever ravenous organisms which surround us.

The losses to food supplies and other products by insects alone amounts to 100 millions of dollars a month in the United States. And the parasites cause losses in sickness and premature deaths each year of many millions more. Then there are the destructive rodents and other animals which add largely to our burdens of support. These enemies next to wars and fungi are the most destructive agencies on earth. Could they but be eliminated man’s struggle against opposing forces would be in large measure overcome. The results of recent work in economic zoology, both in regard to the destruction of enemies and protection of useful mammals, birds and fishes, furnish a bright outlook for the future.

_Protozoology._—Partly as an experimental field for the solution of general biological problems and partly because of its practical applications the study of protozoa has now developed into a special science.

The results of the investigations of Calkins, Woodruff, Jennings and others have greatly supplemented our understanding of the signification of such important biological phenomena as reproduction, sexual differentiation, conjugation, tropisms, and metabolism.

From an economic standpoint the protozoa have recently been shown to be of the greatest importance because of the human and animal diseases for which they are responsible.

_Parasitology._—The animal parasites of man, domesticated animals and plants include numerous species of protozoa, worms, and insects. Together with the bacteria and a few higher fungi they cause all communicable diseases. When we consider that not only our health but also our entire food supply is dependent upon the elimination of these organisms we must admit that parasitology is the most important economically of all the sciences.

The reports of the investigations of Stiles and his associates in the Hygienic Laboratory and of Ransom and his staff in the Bureau of Animal Industry are widely distributed by the federal government. The systematic studies so ably begun by Joseph Leidy in the middle of the last century have been continued by Ward, Linton, Pratt, Curtis and others on the parasites of many groups of animals.

_Economic Entomology._—Another extremely important biological science, the practical applications of which are second only to those of parasitology in importance, is entomology. In the last few years economic entomology has exceeded any of the other branches of biology in the number of its investigators. The American Association of Economic Entomologists has a membership of about five hundred. The work of most of these is supported by appropriations from the State and federal governments, and the results of their investigations are widely published.

It is now well known that some of the protozoon parasites are conveyed from man to man only through the bites of insects. The local eradication of several of our most fatal diseases has recently been brought about by the application of measures to destroy such insects. This is the greatest triumph of economic zoology.

_Economic Ichthyology._—The U. S. Fish Commission has for many years been actively engaged in investigations on the food fishes, including methods for increasing the food supply by suitable protection and artificial propagation. The work includes also edible and otherwise useful mollusks and crustacea. Their marine and fresh-water laboratories have also been of great service to general biological science.

_Economic Ornithology and Mammalogy._—In addition to the local bird clubs and the American Ornithologists Union for the study and preservation of bird and mammal life, the Bureau of Biological Survey has for some years conducted investigations on the economic importance of the various species. The publications of this Bureau are of great value both in determining the economic status of our birds and mammals, and also in recommending means for the protection of the beneficial species and the destruction of the injurious. Several of the States issue similar publications.

_Genetics._

One of the most interesting chapters in biology relates to the development of the modern science of heredity, or genetics.

Previous to the year 1900, when the Mendelian principle of inheritance was re-discovered, the relative importance of heredity and of environment in the development of an organism was little understood. It is true that Weismann had insisted on the independence of soma and germplasm some years earlier (1883), but the body of the individual was still generally considered the key to its inheritance.

The recognition of the general application of Mendel’s discovery gave a great impetus to experimental breeding both in plants and animals. While heretofore it had been necessary to depend upon the somatic characters as evidence of the hereditary constitution of an individual, it now became possible, knowing the hereditary constitution of the parents of any pair of individuals, to predict with almost mathematical certainty the characters of their possible offspring.

In general, the laws of possible chance combinations of any group of characters determine the probability of any particular offspring possessing one or many of those characters. The physical basis for such Mendelian inheritance is evidently the chance combinations of chromosomes which result from the processes of maturation and union of the germ cells.

Certain limitations to the law are met with because the relatively small number of chromosomes involves linkage of genes, because of the occasional interchange of groups of genes between homologous chromosomes, and because the relative activity or potency of any particular gene may differ in different races, and, finally, because the normal activity of any given gene may be modified or inhibited by the action of other genes. It is by no means certain, however, that all inheritance is Mendelian, for there still remains much evidence that the hereditary basis of certain characters may be resident in the cytoplasm, rather than in the chromosomes. A recent book by Morgan, Sturtevant, Müller and Bridges (1915), entitled “the mechanism of Mendelian heredity” gives the cytological explanation of Mendelian inheritance.

Americans have from the first taken a leading part in this field of research and have been quick to recognize its practical applications to the improvement of breeds in both animals and plants. This prominent position is largely due to the experimental work of Castle, Davenport, Morgan, Jennings, Pearl, and their co-workers on animals and that of East, Emerson, Davis, Hayes and Shull on plants.

The geneticist now realizes that the appearance of the body (phenotype) gives but little clue to the inheritance (genotype). That two white flowers produce only purple offspring, or two white fowls only deeply colored chickens, or that a pair of guinea pigs, one of which is black and the other white, have only gray agouti offspring, while other apparently similar white flowers or white animals produce offspring like themselves, is now readily comprehensible and mathematically predictable.

The most important application of our newly acquired knowledge of inheritance is in the improvement of the human race. The wonderful opportunity in this direction must be apparent to all. The welfare of humanity depends upon the immediate adoption of eugenic principles. The Eugenics Record Office has secured many of the essential data.

With the destruction of the world’s best germ plasm at a rate never equalled before, the outlook for the future race would be appalling were it not for the hope that with the advent of a righteous peace will come a realization of the necessity of applying these new biological discoveries to improving the races of men. That the discoveries have been made too late in the world’s history to be of such use to humanity must not be thought possible.

_Evolution._

Previous to the publication of Darwin’s “Origin of Species” in 1859, American zoologists were generally inclined toward special creation, in spite of the evidences for evolution which had been presented by Erasmus Darwin, Buffon, Lamarck, and Geoffroy St.-Hilaire. This attitude of mind continued for some years after the publication of the natural selection theory of Darwin and Wallace. This was in part due to the powerful influence of Louis Agassiz and others who bitterly opposed the Darwinian theory. The influence of Asa Gray in gaining a general acceptance for this theory is explained in the following chapter.

A modified Lamarckian doctrine was widely accepted in the last quarter of the century, due largely to the influence of Cope, Hyatt and Packard. The inheritance of “acquired characters” demanded by this theory seems incompatible with the discoveries of recent times, so that “to-day the theory has few followers amongst trained investigators, but it still has a popular vogue that is wide-spread and vociferous.”[183]

The origin of new varieties and species by accidental and fortuitous modifications (mutations) of the germplasm is now the most widely accepted theory of evolution.

Some of the most important discoveries regarding the origin of new forms have been recently made by Morgan and his pupils. From a stock of the common fruit fly (_Drosophila ampelophila_) more than 125 new types have arisen within six years. Each of these types breeds true. “Each has arisen independently and suddenly. Every part of the body has been affected by one or another of these mutations.” To arrange these mutations arbitrarily into graded series would give the impression of an evolutionary series, but this is directly contrary to the known facts concerning their origin, for each mutation “originated independently from the wild type.” “Evolution has taken place by the incorporation into the race of those mutations that are beneficial to the life and reproduction of the individual.” This evolutionary process is usually accompanied by the elimination of those forms which have remained stable or which have developed adverse mutations.

A question that is being vigorously debated at this time concerns the possible effects of selection on the hereditary factors. Are the genes fixed both qualitatively and quantitatively or does a given gene vary in potency under different conditions and in different individuals? In the former case selection can only separate the existing genes into separate pure strains. But if the gene be quantitatively variable, then selection will result in the establishment of new types.

Castle has long stoutly maintained the effect of such selection, and his forces have recently been augmented by Jennings. The experimental work now in process will doubtless yield a decisive answer.

_Conclusion._

A comparison of the simple descriptive natural history of a century ago with the foregoing manifold developments of modern biology will indicate the wonderful progress which has occurred during this period. The path has led from the crude methods of the almost unaided eye and hand to the applications of the most delicate experimental apparatus. For the marvelous success which zoology has attained has been possible only by the skillful use of scalpel, microscope, microtome and other mechanical devices and by the refined methods of the chemist and physicist.

The central truth to which all these discoveries consistently point is the unity and harmony of all biological phenomena, and indeed of all nature. No longer does the zoologist find any demarcated line separating his field of research from that of the botanist or the chemist or even of the physicist, for all the natural sciences obviously deal with closely associated phenomena. The aim of the future will be both to complete fields of study already marked out and to derive a comprehensive explanation of the general principles involved.

_Notes._

Footnote 172:

Proc. Biol. Soc. Washington, =3=, 35, 1886.

Footnote 173:

Ibid., =4=, 9, 1888. Both of these papers are reprinted in Ann. Rept.
Smithsonian Inst., 1897, U. S. Nat. Mus., Pt. 2, pp. 357–466, 1901.

Footnote 174:

Louis Agassiz: his Life and Correspondence, by Elizabeth Carey
Agassiz, p. 145, 1885.

Footnote 175:

List of North American Land Mammals in the United States National
Museum, 1911. Bull. 79, U. S. Nat. Mus., 1912.

Footnote 176:

Birds of North and Middle America, Bull. 50, parts I-VII, U. S. Nat.
Mus., 1901–1916.

Footnote 177:

Report U. S. Nat. Mus. for 1898, pp. 153–1270, 1900.

Footnote 178:

Bull. 34, U. S. Nat. Mus., 1889.

Footnote 179:

Bull. 47, parts I-IV, U. S. Nat. Mus., 1896–1900.

Footnote 180:

J. Loeb, The Organism as a Whole, p. 126, 1916.

Footnote 181:

The Germ-cell Cycle in Animals, 1914.

Footnote 182:

The Cell in Development and Inheritance, 1896; second edition, 1900.

Footnote 183:

Morgan, T. H. A critique of the theory of evolution, p. 32, 1916.

XIII
THE DEVELOPMENT OF BOTANY SINCE 1818

By GEORGE L. GOODALE

“_Our Botany, it is true, has been extensively and successfully
investigated, but this field is still rich, and rewards every new
research with some interesting discovery._”

Such are the words with which the sagacious and far-sighted founder of the American Journal of Science and Arts, in his general introduction to the first volume, alludes to the study of plants. It is plain that the editor, embarking on this new enterprise, appreciated the attractions of this inviting field and sympathetically recognized the good work which was being done in it. It is not surprising, therefore, to find that he welcomed to the pages of his initial number contributions to botany.

_Early Botanical Works._—The collections of dried and living North American plants, which had been carried from time to time to botanists in Europe, had been eagerly studied, and the results had been published in accessible treatises. Besides these general treatises, there had been issued certain works, wholly devoted to the American Flora. Among these latter may be mentioned Pursh’s “Flora” (1814) and Nuttall’s “Genera” (1818). There were also a few works which were rather popular in their character, such as Amos Eaton’s “Manual of Botany for North America” (1817), and Bigelow’s “Collection of the Plants of Boston and environs” (1814). These handbooks were convenient, and possessed the charm of not being exhaustive; consequently a botanist, whether professional or amateur, was stimulated to feel that he had a good chance of enriching the list of species and adding to the next edition.

_The Early Years of Botany in the Journal._

At that time, the botanists had no journal in this country devoted to their science. Here and there they found opportunity for publishing their discoveries in some medical periodical or in a local newspaper. Hence American botanists availed themselves of the welcome extended by Silliman to botanical contributors to place their results on record in a magazine devoted to science in its wide sense. Specialization and subdivision of science had not then begun to dissociate allied subjects, and, consequently, botanists felt that they would be at home in this journal conducted by a chemist. Botanists responded promptly to this invitation with interesting contributions.

It is well to remember that the appliances at the command of naturalists at the date when the Journal began its service, were imperfect and inadequate. The botanist did not possess a convenient achromatic microscope, and he was not in possession of the chemical aids now deemed necessary in even the simplest research. Hence, attention was given almost wholly to such matters as the forms of plants and the more obvious phenomena of plant-life. In view of the poverty of instrumental aids in research, the results attained must be regarded as surprising.

In the very first volume of the Journal, bearing the date of 1818, there are descriptions of four new genera and of four new species of plants; certainly a large share to give to systematic botany. Besides these articles, there are some instructive notes concerning a few plants, which up to that time had been imperfectly understood. There are four Floral Calendars which give details in regard to the blossoming and the fruiting of plants in limited districts, a botanical subject of some importance but likely to become tedious in the long run. Just here, the skill of the editor in limiting undesirable contributions is shown by his tactful remark designed to soothe the feelings of a prolix writer whose too long list of plants in a floral calendar he had editorially cut down to reasonable limits. The editor remarks, “such extended observations are desirable, but it may not always be convenient to insert very voluminous details of daily floral occurrence.” It is convenient to consider by themselves some of the botanical contributions published in the first series of volumes of the Journal during a period of twenty years, the period before Asa Gray became actively and constantly associated with the Journal.

In systematic and geographical botany one finds communications from Douglass and Torrey (=4=, 56, 1822) on the plants of what was then the Northwest; Lewis C. Beck (=10=, 257, 1826; =11=, 167, 1826; =14=, 112, 1828) contributed valuable papers on the botany of Illinois and Missouri; there is a literal translation by Dr. Ruschenberger (=19=, 63, 299, 1831; =20=, 248, 1831; =23=, 78, 250, 1833) of a very long list of the plants of Chili; Wolle and Huebener (=37=, 310, 1839) gave an annotated catalogue of botanical specimens collected in Pennsylvania; Tuckerman (=45=, 27, 1843) presented communications in regard to numerous species which he had examined critically; Darlington (=41=, 365, 1841) published his lecture on grasses; Asa Gray (=40=, 1, 1841) gave an instructive account of European herbaria visited by him, and he contributed also a charming account (=42=, 1, 1842) of a botanical journey to the mountains of North Carolina. The most extensive series of botanical communication at this time was the Caricography by Professor Dewey of Williams College, presented in many numbers of the Journal; the first of these in =7=, pp. 264–278, 1824. There were also descriptions of certain new genera, and species, and critical studies in synonyms.

Cryptogamic botany is represented in the first series of volumes of the Journal by L. C. Beck’s (=15=, 287, 1829) study of ferns and mosses, by Bailey’s (=35=, 113, 1839) histology of the vascular system of ferns, by Fries’ Systema mycologicum (=12=, 235, 1829), and by De Schweinitz (=9=, 397, 1825) and Halsey, who had in hand a cryptogamic manual. There are two important papers by Alexander Braun, translated by Dr. George Engelmann, one on the Equisetaceæ of North America (=46=, 81, 1844) and the other on the Characeæ (=46=, 92, 1844).

Vegetable paleontology had begun to attract attention in many places in this country, and therefore the translated contributions by Brongniart on fossil plants were given space in the Journal. Plant-physiology received a good share of attention either in short notices or in longer articles. Such titles appear as, the respiration of plants, the circulation of sap, the excrementitious matter thrown off by plants, the effects of certain gases and poisons on plants, and the relations of plants to different colored light. One of the most important of the notes is that in which is described the discovery by Robert Brown (=19=, 393, 1831) of the constant movement of minute particles suspended in a liquid, first detected by him in the fovilla of pollen grains, and now known as the Brownian (or Brunonian) movement. The heading under which this note appears is of interest, “The motion of living particles in all kinds of matter.”

One side of botany touches agriculture and economics. That side was represented even in the first volume of the Journal by a study of “the comparative quantity of nutritious matter which may be obtained from an acre of land when cultivated with potatoes or wheat.” Succeeding volumes in this series likewise present phases which are of special interest regarded from the point of view of economics; for example, those which treat of rotation of crops and of enriching the soil. Probably the economic paper which may be regarded as the most important, in fact epoch-making, is the full account of the invention by Appert of a method for preserving food indefinitely (=13=, 163, 1828). We all know that Appert’s process has revolutionized the preservation of foods, and in its modern modification underlies the vast industry of canned fruits, vegetables and so on. There are suggestions, also, as to the utilization of new foods, or of old foods in a new way, which resemble the suggestions made in these days of food conservation. For example, it is shown that flour can be made from leguminous seeds by steaming and subsequent drying, and pulverizing. There are excellent hints as to the best ways of preparing and using potatoes, and also for preserving them underground, where they will remain good for a year or two. It is shown that potato flour can be made into excellent bread. Another method of making bread, namely from wood, is described, but it does not seem quite so practicable. There are interesting notes on the sugar-beet as a source of sugar, and here appears one of the earliest accounts of the Assam tea-plant, which was destined to revolutionize the tea industry throughout the world. Cordage and textile fibers of bark and of wood should be utilized in the manufacture of paper. In fact one comes upon many such surprises in economic botany as the earlier volumes of the Journal are carefully examined.

Early numbers of the Journal present with sufficient fullness accounts of the remarkable discovery by Daguerre and others of a process for taking pictures by light, on a silver plate or upon paper (=37=, 374, 1839; =38=, 97, 1840, etc.). Before many years passed, the Journal had occasion to show that these novel photographic delineations could be made useful in the investigation of problems in botany. In the pages of the Journal it would be easily possible to trace the development of this art in its relations to natural history. Silliman possessed great sagacity in selecting for his enterprise all the novelties which promised to be of service in the advancement of science. In 1825 (=9=, 263) the Journal republished from the Edinburgh Journal of Science an essay by Dr. (afterwards Sir) William Jackson Hooker, on American Botany. In this essay the author states that “the various scientific Journals” which “are published in America, contain many memoirs upon the indigenous plants. Among the first of these in point of value, and we think also the first with regard to time, we must name Silliman’s Journal of Science.” The author enumerates some of the contributors to the Journal and the titles of their papers.

It has been a useful practice of the Journal, almost from the first, to transfer to its pages memoirs which would otherwise be likely to escape the notice of the majority of American botanists. The book notices and the longer book reviews covered so wide a field that they placed the readers of the Journal in touch with nearly all of the current botanical literature both here and abroad. These critical notices did much towards the symmetrical development of botany in the United States. And as we shall now see, the Journal notices and reviews in the hands of Asa Gray continued to be one of the most important factors in the advancement of American botany.

_Asa Gray and the Journal._

In 1834 there appears in the Journal (=25=, 346) a “Sketch of the Mineralogy of a portion of Jefferson and St. Lawrence Counties, New York, by J. B. Crawe of Watertown and A. Gray of Utica, New York.” This appears to be the first mention in the Journal of the name of Dr. Asa Gray, who, shortly after that date, became thoroughly identified with its botanical interests. In the early part of his career both before and immediately after graduating in medicine, Gray gave much attention to the different branches of natural history in its wide sense. He not only studied but taught “chemistry, geology, mineralogy, and botany,” the latter branch being the one to which he devoted most of his attention. Among his early guides in the pursuit of botany may be mentioned Dr. Hadley, “who had learned some botany from Dr. Ives of New Haven,” and Dr. Lewis C. Beck of Albany, author of Botany of the United States North of Virginia. At that period he made the acquaintance of Dr. John Torrey of New York, with whom he later became associated in most important descriptive work. During the years between his graduation in medicine and 1842, the year when he came to Harvard College, his activities were diverse and intense; so that his preparation for his distinguished career was very broad and thorough. His first visit to Europe, in 1838, brought him into personal relations with a large number of the botanists of Great Britain and the Continent. This extensive acquaintance, added to his broad training, enabled him even from the outset to exert a profound influence upon the progress of his favorite science. He made the Journal tributary to this development. His name first appears as associate editor in 1853, but there are articles in the Journal from his pen which bear an earlier date. The first of these early botanical papers is the following: “A Translation of a memoir entitled ‘Beiträge zur Lehre von der Befruchtung der Pflanzen,’ (contributions to the doctrine of the impregnation of plants, by A. J. C. Corda:) with prefatory remarks on the progress of discovery relative to vegetable fecundation; by Asa Gray, M. D.” (=31=, 308, 1837). Dr. Gray says that he made the translation from the German for his own private use, but thinking that it might be interesting to the Lyceum, he brought it before the Society, with “a cursory account of the progress of discovery respecting the fecundation of flowering plants, for the purpose of rendering the memoir more generally intelligible to those who are not particularly conversant with the present state of botanical science.” The translation occupies six pages of the Journal, while the prefatory remarks fill nine pages. The prefatory remarks constitute an exhaustive essay on the subject, embodied in attractive and perfectly clear language. The translator shows complete familiarity with the matter in hand and gives an adequate account of all the work done on the subject up to the date of M. Corda’s paper. A second important paper by him near this period is his review of “A Natural System of Botany: or a systematic view of the Organization, Natural Affinities, and Geographical Distribution of the whole Vegetable Kingdom; together with the use of the more important species in Medicine, the Arts, and rural and domestic economy, by John Lindley. Second edition, with numerous additions and corrections, and a complete list of genera and their synonyms. London: 1836” (=32=, 292, 1837). A very brief notice of this work in the first part of the volume for 1837 closes with the words, “A more extended notice of the work may be expected in the ensuing number of the Journal.” The extended notice proved to be a critical study of the work, signed by the initials A. G. which later became so familiar to readers of the Journal. Citation of a few of its sentences will indicate the strong and quiet manner in which Dr. Gray, even at the outset, wrote his notices of books. In speaking of the second edition of Professor Lindley’s work, he says:

“It is not necessary to state that a treatise of this kind was greatly
needed, or to allude to the peculiar qualifications of the learned and
industrious author for the accomplishment of the task, or the high
estimation in which the work is held in Europe. But we may properly
offer our testimony respecting the great and favorable influence which
it has exerted upon the progress of botanical science in the United
States. Great as the merits of the work undoubtedly are, we must
nevertheless be excused from adopting the terms of extravagant and
sometimes equivocal eulogy employed by a popular author, who gravely
informs his readers that no book, since printed Bibles were first sold
in Paris by Dr. Faustus, ever excited so much surprise and wonder as
did Dr. Torrey’s edition of Lindley’s Introduction to the Natural
System of Botany. Now we can hardly believe that either the author or
the American editor of the work referred to was ever in danger, as was
honest Dr. Faustus, of being burned for witchcraft, neither do we find
anything in its pages calculated to produce such astonishing effects,
except, perhaps, upon the minds of those botanists, if such they may
be called, who had never dreamed of any important changes in the
science since the appearance of good Dr. Turton’s translation of the
Species Plantarum, and who speak of Jussieu as a writer who has
greatly improved the natural orders of Linnæus.”

In the Journal for 1840 there is a large group of unsigned book reviews under the heading, “Brief notices of recent Botanical works, especially those most interesting to the student of North American Botany.” The first of these short reviews deals with the second section of Part VII of De Candolle’s “Prodromus.” In 1847 the consideration of the “Prodromus” is resumed by the same author and the initials of A. G. are appended. This indicates that Dr. Gray was probably the writer of some of the unsigned book reviews which had appeared in the Journal between 1837 and 1840. Doubtless Silliman availed himself of the assistance of his associates, Eli Ives and others, in New Haven, in the examination of current botanical literature, and it is extremely probable that he early secured help from young Dr. Gray, who had shown himself to be a keen critic as well as a pleasing writer. The notices of botanical works from 1840 bear marks of having been from the same hand. They cover an extremely wide range of subjects. While they are good-tempered they are critical, and they had much to do with the development of botany, in this country, along safe lines.

_Gray as Editor._—Gray’s name as associate editor of the Journal appears in 1853. He had been a welcome contributor, as we have seen, for many years. His influence upon the progress of botany in the United States was largely due to his connection with the Journal. His reviews extended over a very wide range, and supplemented to a remarkable degree his other educational work. It must be permitted to allude here to his sagacity as a writer of educational treatises. In his first elementary text-book, published in 1836, he expressed wholly original views in regard to certain phases of structure and function in plants, which became generally adopted at a later date. His Manual of Botany was constructed, and subsequent editions were kept, on a plan which made no appeal to those who wanted to work on lines of least resistance; in fact he had no patience with those who desired merely to ascertain the name of a plant. In the Journal he emphasizes the desirability of learning all the affinities of the plant under consideration. At a later period, when entirely new chapters had been opened in the life of plants, he sought by his contributions in the Journal to interest students in this wider outlook.

Professor C. S. Sargent has selected with good judgment some of the more important scientific papers by Professor Gray and has republished them in a convenient form.[184] Many of these papers were contributed to the Journal in the form of reviews. These reviews touch nearly every branch of the science of botany. As Sargent justly says, “Many of the reviews are filled with original and suggestive observations, and taken together, furnish the best account of the development of botanical literature during the last fifty years that has yet been written.” In these longer reviews in the Journal, Gray was wont to take a book under review as affording an opportunity to illustrate some important subject, and many of the reviews are crowded with his expositions. For example, in his examination of vonMohl’s “Vegetable Cell” (=15=, 451, 1853) he takes up the whole subject of microscopic structure, so far as it was then understood, and he points out the probable errors of some of Mohl’s contemporaries, showing what and how great were Mohl’s own contributions to histology. Such a review is a landmark in the science. The physiology of the cell and the nutrition of the plant were favorite topics with Professor Gray, and he brought much of his knowledge in regard to them into such a review as that of Boussingault (=25=, 120, 1858) on the “Influence of nitrates on the production of vegetable matter.”

As a systematic botanist, Gray was naturally much interested in the vexed question of nomenclature of plants. One of his most important communications to the Journal is his review, in the volume for 1883 (=26=, 417), of DeCandolle’s work on the subject. He deals with this strictly technical matter much as he did in a contribution to the Journal which he made in 1868 (=46=, 63). In both of these papers he states with clearness the general features of the code of nomenclature. He says explicitly that the code does not make, but rather declares, the common law of botanists. The treatment of the subject at his hands would rightly impress a general reader as showing a strong desire to have common sense applied to doubtful cases, instead of insisting on inflexible rules. For this reason, his rule of practice was not always acceptable to those who were anxious to secure conformity to arbitrary rules at whatever cost. As he said in a paper published in the Journal in 1847 (=3=, 302), “The difficulty of a reform increases with its necessity. It is much easier to state the evils than to relieve them; and the well-meant endeavors that have recently been made to this end, are, some of them, likely, if adopted, to make confusion worse confounded.” This feeling led him to be very conservative in the matter of reform in nomenclature.

This subject of botanical nomenclature illustrates a method frequently employed by Professor Gray to elucidate a difficult matter. He would find in the treatise under review a text, or texts, on which he would build a treatise of his own, and in this way he made clear his own views relative to most of the important phases of botany. When he faced controverted matters, his attitude still remained judicial. While he was tolerant of opinions which clashed with his own, he was always severe upon charlatanism and impatient of inaccuracy. The pages of the Journal contain many severe criticisms at his hands, but an unprejudiced person would say that the severity is merited.

Sometimes, however, instead of reviewing a book or an address, he would follow the custom inaugurated early in the history of the Journal, of making copious extracts, and thus give to its readers an opportunity of examining materials which otherwise might not fall in their way.