Page:Popular Science Monthly Volume 71.djvu/132

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tem of nomenclature and the recognition of the species in general as an objective reality and the unit of classification. But the form of Ray's specific definitions seems to imply that the term "species" in Ray's mind was often more a "differentia," or specific adjective modifying the generic concept, than a fully-developed substantive name, and Ray did not apparently realize the convenience of applying the binomial method of nomenclature universally. Even Linnæus at first introduced the specific, "trivial," or common, name, merely as a marginal index or symbol of the full specific phrase. Ray recognized the considerable variability of species but believed also in their separate creation and fixity. Ray frequently adverts to the internal characters of animals, and even a cursory examination of his book shows that, even by his time, a considerable number of observations on the soft parts of animals had already accumulated.

The work of Ray in botany and zoology fully prepared the way for Linnæus himself, whose epoch may be designated as the Linnæan or legislative epoch, because in his time methods of description, of classification and laws of nomenclature became fully established and settled. Linnæus inherited from Ray and from the scholastic system, the dogma of the separate creation and objective reality of species which became developed and strengthened in his hands as a result of his observations. His dictum was "species tot sunt diversæ quot diversæ formæ ab initio sunt creatæ." The resemblance between members of a single species were hence held to be due to descent from an original pair, and the mutual infertility of species to be the natural penalty of the effort to traverse the gaps established from the beginning.

And now that we have traced briefly the steps leading up to Linnæus, a few words more will summarize the relation of Linnæus to his successors. The sixth epoch in the history of zoology extends from the latter part of the eighteenth to the middle of the nineteenth century, and may be called the anatomical epoch, because, through the labors of Cuvier and his great English pupil and successor, Richard Owen, the taxonomic studies of the Linnæan school were supplemented by the establishment and great development of the sciences of comparative anatomy and paleontology. Cuvier's researches in these sciences further extended the dogma of the fixity of species, but Owen, through his broader knowledge, gradually gave up the idea and became an evolutionist, although not a selectionist. The seventh epoch, the Darwinian, in which happily we are living, has seen the overthrow of the traditional doctrine of the fixity of species, and has initiated the reexamination of all cosmical and terrestrial phenomena in the light of the doctrine of evolution.

Thus the great lawgiver of natural history is seen in his proper perspective, inheriting, on the one hand, the language and