"When found to be such a luxury, it was considered too good to be merely looked at, and it passed from the court to the farm-yard, from farm to farm, from east to west, from north to south. At this present time it is an article of commerce all over France.
"In going from farm to farm, and from country to country, this bird has sustained different conditions of existence, nourishment, and temperature, but never a continuation of its primitive condition that was natural to it in America. The result is, that it has changed, and at this present time the turkey in France bears no resemblance to its savage source. In general, it is smaller, and its rich plumage has undergone a marked change. Some are yellow, others white, some mixed with black, gray, and yellow. Almost all the localities devoted to raising the fowl have caused several new varieties, which have transformed them into races.
"To have thus changed their habits so as to lose resemblance to their first parents, are our French fowls any the less descendants of the wild turkeys of America? Are they less the brothers, or cousins, if you like the term better? Have they ceased to be of the same species? Certainly not!
"That which is characteristic of the turkey is also true of the rabbit. The wild rabbit lives around and about us, on our downs, and in our woods. It resembles our domestic rabbits but little. Among the latter you will see the large and the small, the smooth-haired and the silky; the black and the white, the yellow and the gray, and the mixed. In a word, this species comprises a great number of different races, all constituting one and the same kind with the wild races we see around us. From these facts, which I could multiply, we can deduce an important consequence to which I call your attention. A pair of rabbits left unmolested in a field, would, in a few years, people entire France with their descendants. We have seen how the single coffee-plant, carried by Captain Destiaux, has propagated all the plants now found in America.
"The wild turkeys and their domestic descendants, the wild rabbits and theirs, reduced to captivity, could then be considered by naturalists as all proving equally their descent from one primitive pair.
"This is the secret of species. Having always before our eyes numbers of single groups of animals or vegetables, for one reason or other we hardly consider them as descendants of one only primitive pair; we call what we see a species; if there are differences observable among these groups, they are the races of this species.
"Observe that, in my explanations, I have not given for a certainty the existence of one primitive source for rabbits and turkeys. I do not affirm the fact, as neither observation nor experience—the two guides we must follow in science—teaches anything in this regard. I simply say, all are as though descended from one only primitive pair.
"In summing up the question of species and race, it is not difficult to understand nor to believe, when we know the savage type, and have historical authority which permits us to attach to this type the groups, more or less different, according to their domestication. But when we are ignorant of the savage type, and in want of historical authority, the question becomes extremely difficult at first, because the differences we find in one and the other, and above all, in the different groups, could hardly be considered other than such as characterize different species.
"Happily, physiology comes then to our relief. We find in this science one of those grand and beautiful general laws, which holds and maintains the established order, and which we admire the more we study it. It is the law of crossing, which governs animals as well as vegetables, and is, consequently, applicable to man himself.