Page:Encyclopædia Britannica, Ninth Edition, v. 24.djvu/853

Rh ZOOLOGY 803 Division into mor- phology and phy siology inade quate. v sub- tivision I lased on .istorical ro Tess. systematist as unconscious attempts to construct the genealogical tree or pedigree of plants and animals. Finally, it brought the simplest living matter or formless protoplasm before the mental vision as the starting-point whence, by the operation of necessary mechanical causes, the highest forms have been evolved, and it rendered un avoidable the conclusion that this earliest living material was itself evolved by gradual processes, the result also of the known and recognized laws of physics and chemistry, from material which we should call not living. It abolished the conception of life as an entity above and beyond the common properties of matter, and led to the conviction that the marvellous and exceptional qualities of that which we call &quot; living &quot; matter are nothing more nor less than an exceptionally complicated development of those chemical and physical properties which we recognize in a gradually ascending scale of evolution in the carbon compounds, containing nitrogen as well as oxygen, sulphur, and hydro gen as constituent atoms of their enormous molecules. Thus mysticism was finally banished from the domain of biology, and zoology became one of the physical sciences, the science which seeks to arrange and discuss the phe nomena of animal life and form as the outcome of the operation of the laws of physics and chemistry. NATURE AND SCOPE OF ZOOLOGY. The brief historical outline above given is sufficient to justify us in rejecting, for the purposes of an adequate appreciation of the history and scope of zoology, that simple division of the science into morphology and physio logy which is a favourite one at the present day. No doubt the division is a logical one, based as it is upon the distinction of the study of form and structure in them selves (morphology) from the study of what are the activi ties and functions of the forms and structures (physiology). Such logical divisions are possible upon a variety of bases, but are not necessarily conducive to the ascertainment and remembrance of the historical progress and present signifi cance of the science to which they are applied. As a matter of convenience and as the outcome of historical events it happens that in the universities of Europe, whilst botany in its entirety is usually represented by one chair, the animal side of biology is represented by a chair of so- called zoology, which is understood as the old-fashioned systematic zoology, a chair of human and comparative anatomy, and a chair of physiology (signifying the mechanics, physics, and chemistry of animals especially in relation to man). Fifty years ago the chairs of anatomy and physiology were united in one. No such distinction of mental activities as that involved in the division of the study of animal life into morphology and physiology has ever really existed : the investigator of animal forms has never entirely ignored the functions of the forms studied by him, and the experimental inquirer into the functions and properties of animal tissues and organs has always taken very careful account of the forms of those tissues and organs. A more instructive subdivision of the science of animal biology or zoology is one which shall correspond to the separate currents of thought and mental preoccupation which have been historically manifested in western Europe in the gradual evolution of what is to-day the great river of zoological doctrine to which they have all been rendered contributory. Such a subdivision of zoology, whilst it enables us to trace the history of thought, corresponds very closely with the actual varieties of mental attitude exhibited at the present day by the devotees of zoological study, though it must be remembered that the gathering together of all the separate currents by Darwin is certain sooner or later to entail new developments and branchings of the stream. We accordingly recognize the following five branches of zoological study : 1. Morphoyraphy. The work of the collector and systematist : exemplified by Linnaeus and his pre decessors, by Cuvier, Agassiz, Haeckel. 2. Bionomiw. The lore of the farmer, gardener, sportsman, fancier, and field-naturalist, including thremmatology, or the science of breeding, and the allied teleology, or science of organic adapta tions : exemplified by the patriarch Jacob, the poet Virgil, Sprengel, Kirby and Spence, Wal lace, and Darwin. 3. Zoo-Dynamics, Zoo-Physics, Zoo-Cliemistry. The pursuit of the learned physician, anatomy and physiology : exemplified by Harvey, Haller, Hunter, Johann Miiller. 4. Plasmology. The study of the ultimate corpuscles of living matter, their structure, development, and properties, by the aid of the microscope ; exem plified by Malpighi, Hook, Schwann, Kowalewsky. 5. Philosophical Zoology. General conceptions with regard to the relations of living things (espe cially animals) to the universe, to man, and to the Creator, their origin and significance : exem plified in the writings of the philosophers of classical antiquity, and of Linnaeus, Goethe, Lamarck, Cuvier, Lyell, H. Spencer, and Darwin. It is true that it is impossible to assign the great names of the present century to a single one of the subdivisions of the science thus recognized. With men of an earlier date such special assignment is possible, and there would be no difficulty about thus separating the minor specialists of modern times. But the fact is that as we approach Darwin s epoch we find the separate streams more and more freely connected with one another by anastomosing branches ; and the men who have left their mark on the progress of science have been precisely those who have been instrumental in bringing about such confluence, and have distinguished themselves by the influence of their discoveries or generalizations upon several lines of work. At last, in Darwin we find a name which might appear in each of our subdivisions, a zoologist to whose doctrine all are contributory, and by whose labours all are united and reformed. We shall now briefly sketch the history of these streams of thought, premising that one has (so far as the last three centuries are concerned) but little start of another, and that sooner or later the influence of the pro gress of one branch makes itself felt in the progress of another. MORPHOGEAPHY. Under this head we include the systematic exploration Meaning and tabulation of the facts involved in the recognition of of mor - all the recent and extinct kinds of animals and their dis- pho &quot; r tribution in space and time. (1) The museum-makers of & old days and their modern representatives the curators and describers of zoological collections, (2) early explorers and modern naturalist-travellers and writers on zoo-geography, and (3) collectors of fossils and palaeontologists are the chief varieties of zoological workers coming under this head. Gradually since the time of Hunter and Cuvier anatomical study has associated itself with the more super ficial morphography until to-day no one considers a study of animal form of any value which does not include inter nal structure, histology, and embryology in its scope. The real dawn of zoology after the legendary period of Edward the Middle Ages is connected with the name of an English- Wotton. man, Wotton, born at Oxford in 1492, who practised as a physician in London and died in 1555. He published a treatise De Ditferentiis Animalium at Paris in 1552. In