if evenly distributed among all the species, need not be an adaptive character; whereas, if any one of the species presents it in a slightly different form, the character must be, on this account, necessarily adaptive. In other words, the uniformity with which a generic character occurs among the species of the genus is taken to remove that character from the necessarily useful class, while the absence of such uniformity is taken as proof that the character must be placed within the necessarily useful class. Which is surely no less a _reductio ad absurdum_ with regard to the generic character than the one just presented with regard to its variants as specific characters. And, of course, this twofold absurdity is presented in all cases where a generic character is unequally distributed among the constituent species of a genus. [Illustration: Fig. 4.--Lower Teeth of Orang (after Tomes).] But here is an illustration of another class of cases. Mr. Tomes has shown that the molar teeth of the Orang present an extraordinary and altogether superfluous amount of attachment in their sockets--the fangs being not only exceedingly long, and therefore deeply buried in the jaw-bone, but also curving round one another, so as still further to strengthen the whole[133]. In the allied genera of anthropoid apes there is no such abnormal amount of attachment. Now, the question is, of what conceivable use can it _ever_ have been, either to the existing genus, or to its parent species, that such an abnormal amount of attachment should obtain? It certainly is not required to prevent dislocation of the teeth, seeing that in all allied genera, and even in man himself, the amount of attachment is already so great that teeth will break before they can be drawn by anything short of a dentist's forceps. Therefore I conclude that this peculiarity in the dentition of the genus must have arisen in its parent species by way of what Darwin calls a "fluctuating variation," without utilitarian significance. And I adduce it in the present connexion because the peculiarity is one which is equally unamenable to a utilitarian explanation, whether it happens to occur as a generic or a specific character. [133] _A Manual of Dental Anatomy_, p. 455. Numberless similar cases might be quoted; but probably enough has now been said to prove the inconsistency of the distinction which our opponents draw between specific and all higher characters in respect of utility. In point of fact, a very little thought is enough to show that no such distinction admits of being drawn; and, therefore, that any one who maintains the doctrine of utility as universal in the case of specific characters, must in consistency hold to the same doctrine in the case of generic and all higher characters. And the fact that our opponents are unable to do this becomes a virtual confession on their part of the futility of the generalization which they have propounded[134].