Look at the drawings I have hung at the bottom of the hall. These figures are part of those I employ in the course at the Jardin des Plantes.
I have brought but a small number, but they suffice to give an idea of the principal varieties which the human type presents. You have here individuals taken from nearly every part of the world; and this I regard as a very important point. You see that they differ considerably from each other in color, often also in hair, sometimes in proportions, sometimes in features.
Well, our question is, whether the differences presented by the human groups from which these designs were taken are differences of species, or if they indicate only differences among races that belong to one and the same species.
To answer this question, we must begin by getting a clear idea of what is meant by the words species and race. In fact, the whole discussion turns on these two words.
Unhappily, they have been often taken one for the other, or else they have been badly defined. The discussions which have hence arisen would very quickly cease, if we would study them a little more closely.
Let us see if we cannot get precise ideas without going into details impossible here.
Certainly none of you would ever confound an ass with a horse: not even when a horse is small, and there are horses no larger than a Newfoundland dog; nor when an ass attains the size of an ordinary horse, as, for example, our large asses of Poitou. You say immediately, they are different species: here is a big ass and a little horse. And you say the same on seeing, side by side, a dog and a wolf.
On the other hand, all of you here would give the single name of dog to animals which differ from each other, as do the bulldog and water spaniel, the greyhound and the lapdog, the Newfoundland dog and the King Charles; and you are right.
However, judging by sight alone, even after detailed observation, you see, between the dogs I have just named, differences of size, of proportion, of color, much greater than those which separate the horse from the ass. An ass and a horse of the same size certainly resemble each other much more than the types of dog I have just named.
Further, if you place side by side a black and a white water spaniel, you will not designate them by different names. You will call them both water spaniels, although one is black and the other white.
In the case of vegetables you do exactly the same thing. A red rose and a white rose are equally roses; a pear is always a pear, whether you buy two for a sous in the street, or pay three francs at Chevet.
Well, without doubt, your decision is exactly like that of the