With animals, as with men, sexual association, when it endures, becomes marriage, and results in the family, that is to say, a union of parents for the purpose of protecting their young. The care of the male for his progeny is more rare and tardy than that of the female. Among animals, as among men, the family is at first matriarchal, and it is only in the higher stages of the animal kingdom that the male becomes a truly constituent part of the family group; but even then, except among certain species of birds, his chief care is less to rear the young than to govern in order to protect them. He plays the rôle of a despotic chief, guiding the family when it remains undivided after the rearing of the young, and most frequently acting like a polygamous sultan, without the purely human scruple in regard to incest.
Just as we find amongst animals the two principal types of the human family, the matriarchate and the patriarchate, or rather the maternal and paternal family, so we may observe equally among them all the forms of sexual union from promiscuity up to monogamy; but for enlightenment on these interesting points of sociology, a rapid examination of the animal kingdom is worth far more than all generalities.
II. Marriage and the Rearing of Young amongst Animals.
We shall leave entirely unnoticed the inferior kingdom of zoophytes, which are devoid of coalescing nervous centres, and consequently of conscious life. Even the lower types of molluscs do not begin to think of their progeny; they scatter their eggs as plants do their seeds, and leave them 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.[29]
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.[30]
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 last which it assumes, the outcome of all the previous metamorphoses. But the larval form, though actually transitory, must have been for a long time the permanent form, and it had different tastes and needs. At the present time there are still numbers of insects whose larval existence has a much longer duration than that of the so-called perfect insect (May-flies, cockchafers). There are even larvæ which reproduce themselves. Certain others, even though sterile, have not lost the maternal instinct. Thus at the time of the hatching of the nymphs the larvæ of the termites assist the latter to get rid of their envelope. It is therefore probable that, though now transitory, the larval forms of insects have formerly been permanent; they represent ancestral types, which evolution has by degrees metamorphosed into insects that we call perfect. The larvæ, now actually sterile, descend from ancestors which were not so, and in the larvæ of certain species the maternal instinct has survived the reproductive function.[31]
This is doubtless the case with bees and ants; their workers must represent an ancestral form, having preserved the maternal fervour of its anterior state; the winged form, on the contrary, must be relatively recent. It even appears probable that in the republics of ants and bees the laborious workers may have succeeded, in a certain way, in getting rid of sexual needs which cause animals and even men to commit so many mad actions. With them the old maternal instinct has taken the place ceded to it by sexual instinct, and has become enlarged and ennobled. Their affection is no longer exclusively confined to a few individuals produced from their own bowels, but is shared by all the young of the association. In their sub-œsophagian ganglion one care takes precedence of all others—the care of rearing the young. This is their constant occupation and the great duty to which they sacrifice their lives. Maternal love, usually so selfish, expands with them into an all-embracing social affection. It is not impossible that a psychic metamorphosis of the same kind may one day take place in future human societies.
It would even seem that the workers appreciate the faculty of reproduction all the more for being deprived of it. The queen bee, or rather the fertile female, who is the common mother of all the tribe, has every possible care lavished on her, and is publicly mourned when she dies. If she happens to perish before having young, and then cannot be replaced, the virgin workers despair of the republic; losing for ever “les longs espoirs et les vastes pensées,” they give way to an incurable and mortal pessimism.