Dimorphism is a constant fact in the animal series. Favourable to the male, favourable to the female, indifferent, it starts always from sexual necessity. There is a job to be done: nature divides it equally, or not, between male and female. She knows neither justice nor equality, and lays heavy burdens upon some, even to mutilation and premature death, while she gives to others liberty, leisures, and long hours of pleasant life. It is necessary that the couple reproduce a certain number of beings, equals of the unities of which itself is formed: all means are good which attain this end, and which attain it most speedily and most surely. Nature who is pitiless, is also in a hurry. Her imagination, always active, invents, ceaselessly, new forms which she casts into life, in measure as the earlier born finish their cycle. In superior mammals, and particularly in human species, division of labour is the means used by nature to insure the perpetuity of types. The female insect (leaving aside for the moment social hymenoptera) is provided at once with the organs of her sex and with tools of her trade, with arms for guarding the race; the female human has ceded to man the tools and weapons, here merged in the one instrument, muscle. Or rather, keeping her rights to the instrument, she gives up the use of it. She is neither warrior, huntress, nor mason, nor butcher; she is the female, and the male is the rest. The division of labour supposes community. In order that the female may cede the cares for subsistence and defence to the male, the couple must be established and permanent. The male osmie (sort of solitary bee) sees the light before his female; he could prepare the nest, or at least choose its situation, guide the female to it, work or watch; but he belongs to a series of animals in which the males are merely male organs, and all his rôle is contained in the gestures of mating. The couple is not yet formed. When it is formed, as in other kinds of insects, scarabs, copris, sisyphs, geotrupes, the work is equally shared between the two sexes. Here the parallel ends, for the social evolution of the insect has led to functional differentiations extremely complicated, and if not unknown, at least abnormal, to humanity. Bee society has the female for base, human society has the couple. They are organisms so different that no comparison of them is possible, or even useful. Only in ignorance of them, can one envy bees; a community without sexual relations is really without attraction for a member of the human community. The hive is not a society but a hatchery.