requisite for a full understanding of the significance or aptness of the names.
It was one of the happiest inspirations of Linnæus to segregate all the mammiferous animals—the hairy quadrupeds, the sirenians, and the cetaceans—in a single class. No one before had appreciated the closeness of the relations of the several types, and there was no name for the new class (or concept) as there was for all the others. A name, therefore, had to be devised. It was another happy inspiration that led Linnæus to name the class mammalia. Those who are familiar with the works and ratiocination, and especially the nomenclature of the great Swede, may divine his thoughts and share with him in the execution of his ideas, although he did not give eytmologies. For those 'animalia' which are animals par excellence he would coin a name which would recall that fact. (Animal, be it remembered, is often used in popular converse in the sense of mammal.)
The name in question was evidently made in analogy with animalia. In animalia, the principal component was anima, the 'vital principle' or animal life. (Old Nonius Marcellus well defined and contrasted the word—'animus est quo sapimus, anima qua vivimus.') The singular of the word was animal. In mammalia, the essential component is mamma, breast; the singular should be mammal. The terminal element (-al) was coincident with rather than derived directly from the Latin suffix (-alis) which expressed the idea of resemblance or relationship; anyway, it was used in substantive form, and the idea of possession or inclusion was involved, as in the case of animal, capital, feminal, tribunal—all well-known Latin words. In fine, a mammal is a being especially marked by, or notable for having, mammæ.
The truth embodied in the word was almost immediately appreciated by naturalists at least, and the class of mammals has been adopted ever since the Linnæan period by zoologists. Naturally the new Latin name was to some extent replaced by names in the vernacular tongues of most nations.
In the accommodating English alone the Latin word was adopted with only a change in its ending, and thus the class name mammals was introduced, and the singular form—mammal—followed as a matter of course, and by chance (or rather the genius of language) exactly coincided in form with the singular of the Latin word.
Not only had the name nothing to do with the alleged derivative Latin words. It was not admitted at all into the vernacular speech of
- The assertion of Owen that Aristotle fully recognized the class of mammals under the name Zootoca is without proper foundation. Long ago, in the American Naturalist (VII, 458), I showed that different passages in Aristotle's books negatived such a statement and that the word zootoka was not used as a substantive.