Page:The evolution of marriage and of the family ... (IA evolutionofmarri00letorich).pdf/40

 exposed to all chances. We must go to the superior molluscs to see any care of offspring awakening. In this order, indeed, the most highly developed species watch more or less over their eggs. The taredos carry them stuck together in rings round their bodies; snails often deposit them in damp ground, or in the trunk of a tree; cephalopods fix them in clusters round algæ, and sometimes watch them till they open, after which they leave them to get on as they can in the great world.

With spiders and insects the eggs are often the object of a solicitude and even prolonged forethought, which rejoice greatly the lovers of design. We must observe, however, that the males of spiders and that of the greater number of insects entirely neglect their young; it is again in the female that the care for offspring first awakens. And this is natural, for the eggs have been formed in her body; she has laid them, and has been conscious of them; they form, in a way, an integral part of her individuality.

The females of spiders also take care of their eggs after laying them, enclose them in a ball of thread arranged in cocoons, carry them about with them, and at the moment of hatching set them free, one by one, from the envelope. Amongst some species there is even a certain rearing of the young. Thus the Nemesia Eleonora lives for some time in her trapped nest with her young, numbering from twenty to forty.

With insects maternal forethought sometimes amounts to a sort of divining prescience, which the doctrine of evolution alone can explain. There is really something wonderful in the actions of a female insect, as she prepares for her descendants, whom she will never see any more than she has seen her own parents, a special nourishment which differs from her own. It is thus that the sphinx, the pompilus, the sand-wasp, and the philanthus dig holes in the sand, in which they deposit with the eggs a suitable food for the future larvæ.

In order to understand these facts, apparently so inexplicable, we must look not only to the powerful influence of selection, but also to the zoögenic past of the species. With the insect the perfect form is always the