Biology - The Science Of Life
( Originally Published 1909 )
LIFE, that strange, mysterious, unknown something which flies through the viewless air, flashes through the ocean's depths, blushes in the petals of a rose and manifests itself in a thousand marvelous forms can science grasp, define or explain it? Death, that wondrous change which sooner or later stills the activities of all forms of life and returns them to the realm of the lifeless what is its nature? Why is it necessary? Can science understand or control it? These inquiries and others like them which have troubled the human mind in all ages are the fundamental problems of the science of life.
With the dawn of human consciousness there must have come the realization that this is an earth with two worlds the living and the lifeless. The progress of the ages has not lessened the contrast; and today, men of science, recognising the great chasm between life and death, between the living and the lifeless on the earth, are compelled to group the natural sciences into the Biological Sciences dealing with living things or organisms; and the Abiological Sciences, or Physical Sciences, dealing with lifeless matter. The biological sciences are known collectively as biology, which is therefore often defined as the science of life, of living things, or of living matter. "But living matter," say Sedgwick and Wilson in their 'General Biology.' "is only ordinary matter which has entered into a peculiar state or condition. And hence biology is more precisely defined as the science which treats of matter in the living state."
If the term biology be used in its widest sense of Life lore to include all the results of the scientific study of living creatures, it may be said to have had its foundations in antiquity. But if the term is restricted to the use as defined above that is, to the study of the vital phenomena common to both plants and animals it is quite modern.
Biology is not a new name for the older science known as Natural History, nor is it, as is often thought, a combination of botany and zoology, it is rather a unified science of life. Taken in this sense, the science has been in existence but little more than a hundred years. The history of its development is the history of the splitting up of the Natural History of earlier times into the separate sciences known to-day, physics, chemistry, botany, zoology, etc.; a recognition of the essential similarity of the vital functions of all living things, plants or animals; and the development of a separate science for the study of these phenomena. Huxley, in his essay "On the Study of Biology," writes of its history in these words :
"At the revival of learning, knowledge was divided into two kinds the knowledge of nature and the knowledge of man; for it was the current idea then and a great deal of that ancient conception still remains that there was a sort of essential antithesis, not to say antagonism, between nature and man ; and that the two had not very much to do with one another, except that the one was oftentimes exceedingly troublesome to the other. Tho it is one of the salient merits of our great philosophers of the seventeenth century, that they recognised but one scientific method, applicable alike to man and to nature, we find this notion of the existence of a broad distinction between nature and man in the writings both of Francis Bacon and of Thomas Hobbes. Hobbes says : 'The register of knowledge of fact is called history. Whereof there be two sorts, one called natural history ; which is the history of such facts or effects of nature as have no dependence on man's will; such as are the histories of metals, plants, animals, regions and the like. The other is civil history; which is the history of the voluntary actions of men in commonwealths.' "
Thus all history of fact was divided into these two great groups of natural and of civil history. As time went on, and the various branches of human knowledge became more distinctly developed and separated from one an-other, it was found that some were much more susceptible of precise mathematical treatment than others. The publication of the "Principia" of Newton showed that precise mathematical methods were applicable to those branches of science such as astronomy, and what is now called physics, which occupy a very large portion of the domain of what the older writers understood by natural history.
Time went on, and yet other branches of science developed themselves. Chemistry took a definite shape; and since all these sciences, such as astronomy, natural philosophy and chemistry, were susceptible either of mathematical treatment or of experimental treatment, or of both, a broad distinction was drawn between the experimental branches of what had previously been called natural history and the observational branches those in which experiment was (or seemed) of doubtful use, and where, at that time, mathematical methods were inapplicable.
Under these circumstances the old name of "Natural History" stuck by the residuum of those phenomena which were not, at that time, susceptible of mathematical or experimental treatment ; that is to say, those phenomena of nature which come now under the general heads of physical geography, geology, mineralogy, the history of plants, and the history of animals. It was in this sense that the term was understood by the great writers of the middle of the last century, Buffon and Linnaeus, by Buffon in his great work, the 'Histoire Naturelle Générale,' and by Linnaeus in his splendid achievement, the "Systema Naturae." The subjects they deal with are spoken of as "Natural History," and they called themselves and were called "Naturalists." It is clear that such was not the original meaning of these terms; but that they had by this time, acquired a signification widely different from that which they possessed primitively.
Despite the marvelous progress made by science at the latter end of the eighteenth and the beginning of the nineteenth century, thinking men began to discern that under this title of "Natural History" there were included very heterogeneous constituents. For example, it was not hard to see that geology and mineralogy were, in many respects, widely different from botany and zoology; that a man might obtain an extensive knowledge of the structure and functions of plants and animals with-out having need to enter upon the study of geology or mineralogy, and vice versa; and, further as knowledge advanced, it became clearer that there was a great analogy, a very close alliance, between those two sciences, of botany and zoology, which deal with living beings, while they are much more widely separated from all other studies. Therefore, it is not wonderful that, at the beginning of the nineteenth century, in two different countries, and apparently without any intercommunication, two famous men clearly conceived the notion of uniting the sciences which deal with living matter into one whole, and of dealing with them, as one discipline.
In fact, there were three men to whom this idea occurred contemporaneously, altho but two who carried it into effect, and only one who worked it out completely. These persons were the eminent physiologist Bichat; the great naturalist Lamarck, in France, and a distinguished German, Treviranus. Bichat assumed the existence of a special group of "physiological" sciences. Lamarck, in a work published in 1801, for the first time made use of the name "Biologie," from the two Greek words which signify a discourse upon life and living things. About the same time it occurred to Treviranus, that all those sciences which deal with living matter were essentially and fundamentally one, and ought to be treated as a whole ; and, in the year 1802, he published the first volume of what he also called "Biologie." Treviranus's great merit lies in this, that he carried out his idea, and wrote the very remarkable work above mentioned. It consists of six volumes, and occupied its author for twenty years from 1802 to 1822. That is the origin of the term "Biology," which denotes the whole of the sciences which deal with living things, whether they be animals or whether they be plants.
After discussing the origin of the science of biology, the next questions that naturally present themselves are with reference to the extent and nature of its scope. In its strict technical sense, Biology denotes all the phenomena which are exhibited by living things, as distinguished from those which are not living; but while that secondary definition suffices in the domain of the lower animals and plants, it is found to involve considerable difficulties in an investigation of the higher forms of living things. For whatever views may be entertained about the nature of man, one thing is perfectly certain, that he is to be considered a living creature. Hence, a strict interpretation of such a definition must include man and all his ways and works under the head of biology ; in which case, psychology, politics, and political economy would be absorbed into the province of Biology.
It has been found convenient to set human psychology and sociology apart from biology, but the progress of these sciences in the past century has clearly shown that they are intrinsically inseparable from biology or that they at least find many of their fundamental principles in the general science of life.
Even without the psychological and sociological phases of human life, the field covered by biology as thus understood is so wide as to necessitate a subdivision of the subject into a number of branches, to which are usually assigned the rank of distinct sciences. As already pointed out, the usual division of biology into botany and zoology has the great advantage of practical convenience, since, as a matter of fact, most biologists devote their attention mainly either to plants alone, or to animals alone. From a scientific point of view, however, a better subdivision is into Morphology and Physiology. The former is based upon the facts of form, structure and arrangement, and is essentially statical; the latter upon those of action or function, and is essentially dynamical. But morphology and physiology are so intimately related that it is impossible to separate either subject absolutely from the other, for which reason authors speak of plant morphology and animal morphology, plant physiology and animal physiology.
There are further subdivisions. Thus on the plant or animal side of biology there are the following subsciences: Anatomy the science of structure, the term being usually applied to the coarser and more obvious composition of plants or animals; Histology microscopical anatomy, the ultimate analysis of structure by the aid of the microscope, separated from anatomy only as a matter of convenience; Taxonomy the classification of living things, based chiefly on the phenomena of structure; Distribution —considering the position of living things in space and time, their distribution over the present face of the earth and their distribution and succession at former periods, as displayed in fossil remains; Embryology the science of development from the germ, including many problems pertaining both to morphology and physiology; and Physiology (including pathology) the special science of the functions of the individual in health and in disease. The very highly specialized biological sciences, ornithology (birds), entomology (insects), herpetology (reptiles), conchology (shells), lichenology (lichens), bryology (mosses), mycology (fungi), etc., apply to the groups of animals and plants indicated by the names of these sciences. They are chiefly concerned with classification and hence deal largely with details of structure.
While the scope of biology may be thus skeletonized, it must be pointed out with emphasis that the common conception of biology as simply a combination of botany and zoology is one which tho convenient and indeed necessary for practical purposes, and for extended study and re-search, does not concern the present treatment. Dealing with organic structures and functions in connection with their causes, conditions, concomitants and consequences, Biology cannot divide itself into Animal Biology and Vegetable Biology; since the same fundamental classes of phenomena are common to both. It is with these general vital phenomena common to both plants and animals that this work is concerned, hence in considering the general problems of the science of biology the familiar division into botany and zoology is recognised only occasionally as a matter of convenience. Undoubtedly confusion will be avoided if it is kept in mind that 'General Biology' is the subject under view. This term does not designate a particular member of the group of biological sciences, "but is only a convenient phrase, which has recently come into use for the general introductory study of biology. It includes a description of the general properties of living matter as revealed in the structures and actions of living things, and may serve as the basis for subsequent study of more special branches of the science. It deals with the broad characteristic phenomena and laws of life as they are illustrated by the thoro comparative study of a series of plants and animals taken as representative types; but inasmuch as all the varied phenomena which come under observation are in the last analysis due to the properties of matter in the living state, the biologist ever remembers that this matter and these properties are the goal of study."