in this book.” Buifon, De Blainville, St Hilaire, and others,[1] have used similar terms of eulogy. One modern zoologist, Professor Sundevall of Stockholm, has reckoned up the number of species with which Aristotle showed himself to be more or less acquainted, and he finds them to amount to nearly 500,—the total number of mammals described or indicated being about 70; of birds 150; of reptiles 20; and of fishes 116—making altogether 356 species of vertebrate animals. Of the invertebrate classes about 60 species of insects and arachnids seem to have been known to Aristotle; some 24 crustaceans and annelids; and about 40 molluscs and radiates,[2] At the same time, it must be remembered that Aristotle had no idea of the scientific system of classification which appears in Professor Sundevall’s list. He does not seem to have laboured much at the arrangement of living creatures into natural orders; indeed he could not have succeeded in such an attempt, for want of a sufficient knowledge of anatomy. He was content with the superficial, universally-received, grouping of animals, as walking, creeping, flying, or swimming; as oviparous or viviparous; aquatic or terrestrial; and the like. His book contains a mass of materials, but without much methodic arrangement or trace of system. It pointed the way, however, for his successors to a science of zoology.
The facts given by him of course vary extremely in correctness and in value. In his account of sponges,
