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THE POPULAR SCIENCE MONTHLY.

naturalists. You have answered, just as they do, the question of species and race—a question that at first appears very complicated, because of the confusion before referred to. Here, then, is one more example to prove that, under many circumstances, popular observation and good sense go straight to the mark, as well as the labors of science.

Indeed, let us translate into general scientific language what I have just said of your views, and I am very sure not to be mistaken with regard to them.

The meaning of this judgment is, that an animal or a vegetable may vary within certain limits. The dog remains a dog, whatever its general form, its size, its hair; the pear remains a pear, whatever its size, its savor, the color of its skin.

From these facts, which I simply allude to, it results that these variations may be transmitted by way of generation. You all know that the union of two water spaniels will produce water spaniels; that the union of two bulldogs gives bulldogs.

It results, finally, in a more general way, that individuals of the same species may cease to resemble each other in an absolute manner, may sometimes even take very different characters, without becoming isolated and forming different species. As we have just said, the dog remains a dog, whatever its modifications.

Well, these groups, formed by individuals which have departed from the primitive type, and have formed distinct secondary groups, are precisely the ones that naturalists call races.

You understand why we constantly speak of races of cattle, horses, etc. There is, in fact, but one species of domestic cattle, which has given birth to the race bretonne, as well as to the great cattle of Uri, with their savage aspect, and to the peaceful Durham. We have, again, but one species of domestic horse, and this species has given birth to the little Shetland pony, of which I spoke just now, and to those enormous brewers' horses that we see in the streets of London. Finally, the various races of sheep, goats, etc., have arisen from one and the same species.

We must give more precision to our ideas on this point, because the least vagueness here will make very serious inconvenience. I will cite some further examples taken from vegetables and animals, being careful to choose such as are entirely familiar.

You all know the seed of the coffee tree. Permit me to give its history. You will see that it is instructive.

The coffee tree came originally from Africa, where from time immemorial it has been cultivated on the declivities of Abyssinia that elope toward the Red Sea. About the fifteenth century, something like four hundred years ago, the coffee tree crossed this sea and penetrated into Arabia, where it has since been cultivated, and whence especially we get the famous coffee of Mocha.