We now come to the renaissance epoch. Biological science, and especially zoology, did not respond fully to the impulse of the renaissance movement until literature, politics, astronomy and geographical discovery had made the most signal advances. Hence in Aldrovandi (1522-1605) and Gesner (1516-1565) the superstitions and myths of the middle ages still linger, while the systematic work of future generations is initiated in the extensive, illustrated catalogues and descriptions of plants and animals. On the philosophical side of zoology, the Englishman Wotton, in his "De Differentiis Animalium" (Paris, 1552,) "rejected the legendary and fantastic accretions [of medieval zoology] and returned to Aristotle and the observation of nature" (Lankester) One of the contemporaries of Gesner and Wotton was the founder of anatomy, Andreas Vesalius (1514—1564), who boldly broke with tradition and declared that the source of knowledge of the human body should be not Galen, but the human body itself.
Near the end of this period, the botanist, Cesalpino (Cæsalpinus), of Arezzo (1519-1778), himself a celebrated scholastic philosopher, but animated also by the new idea of direct observation, published his voluminous work "De Plantis" (1583), In this work the confused arrangements of plants of the earlier herbalists are replaced by an orderly classification suggested by the brigades of an army, and founded upon the number, the position and the figure of the reproductive parts. He divided plants into ten great classes, which were again subdivided; to these assemblages he gave monomial names in substantive form. Linnæus says of him that, "though the first in attempting to form natural orders he observed as many as the most successful later writers." (Whewell, op. cit., pp. 282-283.)
We may venture to suggest as a reason for this precocious development of a natural classification of plants the very multiplicity of kinds and the large herbaria and horticultural gardens in existence which necessitated some sort of orderly arrangement, and which would assist the eager student to recognize related series. We note in contrast the delayed progress of the classification of the mammals due to the comparative fewness of known forms, the greater complexity of organization and the difficulties of observation.
Among those who contributed the data for Linnæus's generalizations, no name is more important, at least in the history of vertebrate zoology, than that of John Bay. Accordingly, the fourth epoch under consideration may be termed the Raian epoch, and culminates with the publication in 1693 of Ray's "Synopsis Methodica Aninialium Quadrupedum et Serpentini Generis," which is one of the great landmarks in the history of classification. Ray's debt to the past is shown in the
- Lankester, E. Ray, The History and Scope of Zoology, in "The Advancement of Science," London, 1890, p. 293.