THE NAME MAMMAL AND THE IDEA EXPRESSED/' 



By Theodore Gill. 



One of the most natural of tlie polA^iiorphic groups of the animal 

 kino-dom is the class of mammals, but yet it was less than a century 

 and a half ago that it was recognized. It was. in fact, the fruit of 

 scientitic research and logic and not of ]:)opular recognition. Popular 

 and scientitic classifications of the animal kingdom, far from being 

 parallel or the one merel}- an extension of the other, have been often 

 directly opposed. From the earliest times, the Aryan and Semitic 

 peoples at least considered animals in aggregates with reference to 

 -the functions exercised rather than with reference to agreement in 

 structural details; in the language of the naturalist, they segregated 

 them by physiological characters rathei" than morphological ones. 

 There was, too, a curious association with what were called the 

 ''elements" — earth, water, and air. (Fire was without its animals, 

 unless the fabled salamander be regarded as one.) This association 

 was in olden times generally accepted. It appears in the fJewish tale 

 of creation giyen in Genesis (i. 1, 2, 7, 9, 20, 24); it appears in the 

 Roman niA'thology perpetuated in Oyid's yerse (Metam., I, lines 5-7, 

 21, 22, 72-75). 



In popular natural history, the hairy quadrupeds were associated with 

 the scaly and naked ones as quadi'upeds, the sea-dwelling cetaceans 

 were combined with the scaly tishes in another class, and the \olaiit 

 bats were sometimes grouped with qnadrupeds on account of their 

 obyious likeness to mice, except foi' the. wings, and sometimes with 

 birds because thej could Hy. So all continued to be grouped through 

 the ages. Aristotle did no better, or at any rate little better, than those 

 preceding him and those following him for many centuries. The 

 assertion of Owen that Aristotle fully recognized the class of mam- 

 mals imder the name Zootoca is without proper foundation. Long ago, 

 in the American Naturalist (VII, 45S), I showed that ditferent [)assages 

 in Aristotle's book negatiyed such a statement and that the wovvi 

 zootdka was never used as a substantive. 



«Muoh of the present article was published in September, 1902, in the Popular 

 Science Monthly under the caption "The story of a name — Mammals." 



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