Biologist

“ The biologist cannot fail to be impressed by the fact that his science to-day is, roughly and broadly speaking, in the position which Chemistry and Physics occupied a century ago. It is beginning to reach down from observation to experimental analysis, and from experimental analysis to grasp of principle. Furthermore, as the grasp of principles in physico-chemical science led speedily to an immense new extension both of knowledge and of control, so it is not to be doubted that like effects will spring from like causes in biology. ”

“ Such a speck of living protoplasm as the amoeba is known to biologists as a cell; and of such cells or variations of them the structures of all plants and animals are built up, a plant or animal composed of a single cell being known as a unicellular organism, whereas a plant or animal composed of a plurality of associated cells is known as a multicellular organism. Since such unicellular organisms as the amœba are fairly observable, we may conveniently begin the study of life at that stage of evolution which they have reached. ”

“ His more immediate effort is to inquire into the nature of the existing organism, to ascertain in what measure the complex phenomena of life as they now appear are capable of resolution into simpler factors or components, and to determine as far as he can what is the relation of these factors to other natural phenomena. It is often practically convenient to consider the organism as presenting two different aspects—a structural or morphological one, and a functional or physiological—and biologists often call themselves accordingly morphologists or physiologists. ”

“ The biologists tell us that all this is an entire mistake. They turn to the physical organisation of man. They examine his whole structure, his bony frame and all that clothes it. They resolve him into the finest particles into which the microscope will enable them to break him up. They consider the performance of his various functions and activities, and they look at the manner in which he occurs on the surface of the world. ”

“ This distinction has always existed, but has only lately come into such prominence that it divides biologists into two camps—those who make it their aim to investigate the action of the organism and its parts by the accepted methods of physics and chemistry; and those who interest themselves rather in considering the place which each organism occupies and the part it plays in the economy of Nature. ”

“ The factors of evolution fall under two heads—origin and guidance. The origin of variations lies in mechanical stresses, and chemical or physical influences. Whether these act on the body (and are transmitted by inheritance) or only on the germ, is a question which divides biologists into two schools. In the latter case all variations are fortuitous; in the former the development of tissue-variations has been in direct response to the physical or chemical influences. ”

“ The real fact is, that we biologists are a self-sacrificing people; and inasmuch as, on a moderate estimate, there are about a quarter of a million different species of animals and plants to know about already, we feel that we have more than sufficient territory. ”

“ Members of DIYbio communities who are involved in more sophisticated experiments tend to be trained biologists, not amateurs and, as noted in the previous section, the experiences of amateur members of the DIYbio community demonstrate the challenges posed by tacit knowledge to successfully conduct even rudimentary biological experiments. ”

“ Cytology.—A third conception which contributed to the formulation of modern biology was derived from the facts discovered in connection with the organic cell and protoplasm. The significance of these facts we shall notice later, but here we may simply state that these discoveries offered to students simplicity in the place of complexity. The doctrine of cells and protoplasm appeared to offer to biologists no longer the complicated problems which were associated with animals and plants, but the same problems stripped of all side issues and reduced to their lowest terms. ”

“ Biologists are so largely, and quite wisely, occupied in the study of morphological and physiological problems, which admit of a treatment more exact than the most ardent advocate of the investigation of behaviour, under natural or even under experimental conditions, can claim; they devote, again quite rightly, so large a share of attention to the variation and natural selection of adaptive structure in its adult condition and embryonic stages ”

“ It has already been indicated that ecology bears the closest of relations to morphology and histology on the one side, and to physiology on the other—that it is, indeed, nothing but a rational field physiology, which regards form and function as inseparable phenomena. The closeness with which it touches plant pathology follows directly from this, as pathology is nothing more than abnormal form and functioning. Experimental work in ecology is purely a study of evolution, and the facts of the latter are the materials with which taxonomy deals. ”

“ He is a botanist, and his science is botany. But if the investigation of animal life be his choice, the name generally applied to him will vary according to the kind of animals he studies, or the particular phenomena of animal life to which he confines his attention. If the study of man is his object, he is called an anatomist, or a physiologist, or an ethnologist; but if he dissects animals, or examines into the mode in which their functions are performed, he is a comparative anatomist or comparative physiologist. ”

“ He will study not botany and zoology, which, as I have said, would take him too far away from his ultimate goal; but, by duly arranged instruction, combined with work in the laboratory upon the leading types of animal and vegetable life, he will lay a broad, and at the same time solid, foundation of biological knowledge; he will come to his medical studies with a comprehension of the great truths of morphology and of physiology, with his hands trained to dissect and his eyes taught to see. ”

“ But the study of the relations of the organism to its environment, organic and inorganic, also belongs to physiology in the wider sense; we call this part of it perilogy, or the physiology of relations. To this belong chorology, or the science of distribution (also called biological geography, as it deals with geographical and topographical distribution) , and œcology or bionomy (also recently called ethology) , the science of the domestic side of organic life, of the life-needs of organisms and their relations to other organisms with which they live (biocenosis, symbiosis, parasitism) . ”

“ In the disentanglement of the properties and interactions of these elementary factors, the science we must call to our aid is Physiological Chemistry. The relations of Genetics with the other branches of biology are close. Such work can only be conducted by those who have the good fortune to be able to count upon continual help and advice from specialists in the various branches of Zoology, Physiology, and Botany. ”

“ Then, too, earlier students had only vague notions of the actual structure of a living organism. Beginning with the earliest idea that a plant or an animal exists as a unit organism, to be studied as such, biological science progressed, first to the recognition and study of the individual organs which are contained within the organism; then to the tissues which make up these organs; then (with the coming into use of the microscope as an aid to these investigations) to the cells of which the tissues are composed; then to the protoplasm which constitutes the cell contents ”

“ The reason that the specific truths of nature must be found out in laboratories is that there are too many things mixed together in the fields. The laboratory naturalist endeavors to untangle the confusion of elements in the outdoor environment and to isolate the different factors that affect the life and behavior of an animal, in order that he may be sure with just what he is dealing in his efforts to determine the value of each one separately. ”

“ To the physiologist, however, individual ecology tends to appeal most strongly, and he, perhaps on account of the preponderance of analytical methods in his work, feels that this is the safest and most important aspect. This statement is perhaps also true of most students of animal behavior. This is largely due to the great present need of analytical methods in these lines, and perhaps indicates a stage in the development of their science rather than a permanent condition. ”

“ In zoölogy the environment of an organism means the sum-total of the conditions of life that surround and affect it, such as food, air, water, climate, etc.
We have already stated that as far as evolution is concerned the structures of fundamental importance in an organism are the Germ-Cells; therefore, for our purposes, we will define environment to be the sum-total of the conditions that directly or indirectly influence in any way the germ-cells, by which variations in them may be produced, or through which stability may be maintained. ”

“ It is clear that the organism that best uses its organs has, other things equal, the best chance of survival. It will therefore hand on to its offspring germinal matter with an inherent tendency to make vigorous use of its faculties.
Those who argue thus deny that the body-cells can in any way affect the germ-cells. To account for any continuous increase in faculty, they invoke variation and the selection of favourable varieties. What, then, we may now ask, is, on their view, the mode of origin of variations? ”

“ At present biology as a science is mainly in the descriptive stage, though it is slowly but surely becoming explanatory [Pg 15] and genetic. The developmental or explanatory method is so difficult that every possible expedient—observation, comparison, reflection, experiment, etc.—must be used to secure the proper development of the main phases of ecology. There is a marked tendency in the naturalist to master one system of work, as observation or experiment, and to use it as a tool almost exclusively, turning from one phase of the subject to another, and continuing the use of the same method. ”

“ Moreover, the essentials are found to be the same in the animal kingdom also, and the bearing of all these discoveries on the phenomena of reproduction, variation, and heredity in living organisms has been and is of the highest importance, for they support, control, explain and correct so many of the splendid results of Knight, Kölreuter, Sprengel, Hildebrand and Hermann Müller, and in every direction throw side-lights into the crevices of that magnificent structure, the theory of Natural Selection, erected for all time by our countryman, Charles Darwin. ”

“ The method of control culture, which is carried on in the planthouse, naturally does not possess the fundamental value of the field methods. It is an invaluable aid to the latter, however, since it permits the physical factors to be readily modified and controlled. All these methods are based on the indispensable use of instruments for the measurement of physical factors.
METHOD OF NATURAL EXPERIMENT 188. Selection of species. Species that are producing variants or ecads are found everywhere in nature; those which give rise to mutants seem, however, to be extremely rare. ”

“ For some years the studies remained largely of a systematic nature, and embraced all groups of animals, but long before the close of the century the attention of the majority of the ever increasing group of zoologists was directed into more promising channels for research and there came the development of the sciences of comparative anatomy, physiology, embryology, experimental zoology, cytology, genetics, and the like, while the systematists became specialists in the various animal groups. ”

“ THE data of biology are living plants and animals. These are what nature presents. To these we must always go in order to make a beginning at any investigation. Is one interested in ganglionic cells, or germ cells, or liver secretions, or degenerate organs? He must find some kind of animal that has, or produces, or can yield such things. In making a successful quest for "material," it always turns out that a particular individual plant or animal, one or more, furnishes it. ”

“ It was in that century that the use of the microscope made known the similarity in cellular construction of all organized beings; that the substance, protoplasm, began to be recognized as the physical basis of life and the seat of all vital activities; then, most contagious diseases were traced to microscopic organisms, and as a consequence, medicine and surgery were reformed; then the belief in the spontaneous origin of life under present conditions was given up; and it was in that century that the doctrine of organic evolution gained general acceptance. ”

“ 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. ”

“ The great service of establishing the idea of orderly progress in nature is part of the heritage of work already done. The idea, in so far as it involves living and fossil forms of animals, is owing to the progress of zoology.
Some Practical Applications.—Let us now consider secondly some of the applications of zoological advances to the benefit of mankind. It was owing to the cooperation of botany and zoology that the germ theory of disease was established. The bacteria are, of course, plants. The method of studying their action on animals is zoological. ”