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THE POPULAR SCIENCE MONTHLY
Ray and later writers probably had this passage in mind when they used the descriptive terms "multifido," "bifido," "solidungula," "ungulata," "unguicnlata," "fissipedes." Here also attention is directed to the feet as exhibiting characteristic differences.
This passage evidently directed the attention of later writers to the importance of the teeth as a means of distinguishing and hence of classifying mammals, and we shall see that Ray and, later, Linnaeus were quick to avail themselves of the suggestion.
Although Whewell[5] proves that Aristotle was quite unconscious of the classification that has been ascribed to him, he also admits that "Aristotle does show, as far as could be done at his time, a perception of the need of groups, and of names of groups, in the study of the animal kingdom; and thus may justly be held up as the great figure in the Prelude to the Formation of Systems which took place in more advanced scientific times."
Whewell quotes passages that show recognition of the lack of generic names to denominate natural groups. Aristotle says that "Of the class of viviparous quadrupeds there are many genera,[6] but these again are without names, except specific names, such as man. lion, stag, horse, dog, and the like. Yet there is a genus of animals that have manes, as the horse, the ass, the oreus, the ginnus, the innus, and the animal which in Syria is called heminus (mule). . . . Wherefore," he