In my lectures on this subject I have cited textually the words of the best authorities among men of science respecting the principal groups of fresh and salt water animals; I have passed in review the fauna of the air, beginning with insects; and have dwelt to some extent on fishes and reptiles. I will spare you the enumeration, and will speak of the bird the area of whose habitat is most extended. The peregrine falcon occupies all the temperate and warm regions of the Old and New Worlds, but does not reach the arctic regions, or Polynesia.
In his body, man is anatomically and physiologically a mammal—no more and no less. This class, therefore, interests us more than the others, and furnishes us with more precise knowledge. I will, for that reason, enter more into detail respecting it, taking as my guide the great work of Andrew Murray.
By virtue of their strength, their enormous locomotive powers, and of the continuity of the seas which they inhabit, the cetaceans should seem to be able to play a truly cosmopolitan part. They do not. Each species is cantoned within an area of greater or less extent, beyond which a few individuals may occasionally make excursions, but always to return soon within their bounds. Two exceptions to this general rule have been noted. A rorqual with large flippers, and a northern Balænopterus, natives of temperate and frigid seas, are said to have been found, the first at the Cape, the second at Java. Judging from what Van Beneden and Gervais, the two greatest authorities in cetology; say, these statements are at least doubtful. But, if we accept them as true, it is still the fact that neither species has been met in the seas that wash America and Polynesia. We find nothing else resembling the whales in cosmopolitism, even though it be narrow. Here, also, I spare you the details. You know as well as I do that the species of marsupials, edentates, and pachyderms have their respective countries clearly defined; and that, if the horse and hog are now in America, it is because they have been imported there by Europeans.
A very small number of ruminants inhabit the north of both continents. It is generally agreed to regard the reindeer and the caribou as only races of the same species; Brandt, with some reservations, says as much of the bison and the aurochs, the argali and the big-horn. But none of these species are found in the warm regions of these two quarters, or in all Oceania.
The carnivorous order perhaps offers some similar facts to the preceding. But when we come to the Cheiroptera and the Quadrumana, we do not find a single species common to both continents, or to the rest of the world.
Thus there is not a cosmopolite, after the manner of man, among all organized beings, whether plants or animals. Now, it is