stock. The second hypothesis declares that all these kinds of cats represent divergencies of the original stock, precisely as the Varieties of each kind represent the divergencies of each Species. It is true that each species, when once formed, only admits of limited variations; any cause which should push the variation beyond certain limits would destroy the species,—because by species is meant the group of animals contained within those limits. Let us suppose the original stock from which all these kinds of cats have sprung, to have become modified into lions, leopards, and tigers—in other words, that the gradual accumulation of divergencies has resulted in the whole family of cats existing under these three forms. The lions will form a distinct species; this species varies, and in the course of long variation a new species, the puma, rises by the side of it. The leopards also vary, and let us suppose their variation at length assumes so marked a form,—in the ocelot,—that we class it as a new species. There is nothing in this hypothesis but what is strictly consonant with analogies; it is only extending to Species what we know to be the fact with respect to Varieties; and these Varieties which we know to have been produced from one and the same Species are often more widely separated from each other than the lion is from the puma, or the leopard from the ocelot. Mr. Darwin remarks that "at least a score of pigeons might be chosen, which, if shown to an ornithologist, and he were told that they were wild birds, would certainly, I think, be ranked by him as well-defined species. Moreover, I do not believe that any ornithologist would place the English carrier, the short-faced tumbler, the runt, the barb, the pouter and fantail in the same genus! more especially as in each of these breeds several truly-inherited sub-breeds or species, as he might have called them, could be shown him."
The development of numerous specific forms, widely distinguished from each other, out of one common stock, is not a whit more improbable than the development of numerous distinct languages out of a common parent language, which modern philologists have proved to be indubitably the case. Indeed, there is a very remarkable analogy between philology and zoology in this respect: just as the comparative anatomist traces the existence of similar organs, and similar connections of these organs, throughout the various animals classed under one type, so does the comparative philologist detect the family likeness in the various languages scattered from China to the Basque provinces, and from Cape Comorin across the Caucasus to Lapland—a likeness which assures him that the Teutonic, Celtic, Windic, Italic, Hellenic, Iranic, and Indic languages are of common origin, and separated from the Arabian, Aramean, and Hebrew languages, which have another origin. Let us bring together a Frenchman, a Spaniard, an Italian, a Portuguese, a Wallachian, and a Rhætian, and we shall hear six very different languages spoken, the speakers severally unintelligible to each other, their languages differing so widely that one cannot be regarded as the modification of the other; yet we know most positively that all these languages are offshoots from the Latin, which was once a living language, but which is now, so to speak, a fossil.
