In the higher types of animals, with the longer period of infancy, some amount of care for the young is always shown by the mother. All the mammals, without exception, nurse their offspring for a longer or shorter period. Among the birds the young in many species are tended by both parents, and we find many beautiful examples of parental fosterage and protection. But we find also species, like the cuckoos, which thrust the parental duties on to others; and there are others, such as the megapodes, where the mother trusts the incubation of her eggs to natural agencies, and after placing them in a position to get the heat generated by decaying vegetation or that derived from hot springs, leaves them, and exhibits no apparent care for the future welfare of the family.

Here is something to give us food for thought. And the same surprises meet us as we descend the scale of life. The reptiles show little or no parental care, but strangely enough the toads and frogs, and many fishes, furnish us with examples of remarkable forethought, or apparent forethought, for their offspring; and, let it be noted, this solicitude is in most cases shown by the father and not by the mother. Even more remarkable are the insects, among whom, though still lower in the scale, we find the most wonderful cases of parental sacrifice to be met with anywhere in life. Some of these little creatures, indeed, seem to be endowed with a devotion to their young so insistent, that their lives can be described only as a passion of sacrifice. In truth they live but to give life and die. And accompanying this parental sacrifice, first in supplying food for embryonic development, and also, in some cases, affording fosterage and protection during the early stages of growth, we meet the most varied and wonderful behaviour which seems to prove an intelligence that thinks and plans; and, whatever explanation we try to find for these acts of devotion, we still are far from understanding them. Life has its secrets, and we shall probably fail to penetrate these mysteries. All that is possible to us is to inquire humbly that we may learn a few truths.

But for the sake of clearness, let me cease from generalising and direct our attention to certain definite examples. I will select first the model household of the Minotaurus Typhæus in the order Coleoptera

“The female digs a large burrow which is often more than a yard and a half deep and which consists of spiral staircases, landings, passages and numerous chambers. The male loads the earth on the three-pronged fork that surmounts his head and carries it to the entrance of the conjugal dwelling. Next he goes into the fields in search of harmless droppings left by the sheep, he takes these down to the first storey of the crypt and, with the aid of his trident begins to reduce them to flour, while the mother, right at the bottom, collects and kneads it into huge cylindrical loaves, which will presently become food for the little ones. For three months, until the provisions are deemed sufficient, the unfortunate husband, without taking any nourishment of any kind, exhausts himself in this gigantic work. At last, his task is accomplished. Feeling his end is at hand, so as not to encumber the house with his wretched remains, he spends his last strength in leaving the burrow, drags himself laboriously along and, lonely and resigned, knowing that he is henceforth good for nothing, goes and dies far away amid the stones.”[10]

Here we have exactly the kind of example we are in search of, and the most important thing to observe is the co-operation of the father with the mother in the work of providing for the family: such male devotion is undoubtedly exceptional.

Some measure of parental solicitude is almost universally common, and even among the lowliest creatures we find convincing proof of this. Among the species of limited resources, where the least care is bestowed and the young are left to look after themselves, the eggs are placed by the mother in a suitable environment so that the young can be sure of a sufficiency of food until they can feed themselves. The numerous caterpillars offer a well-known illustration of this primitive care, where it is common for the eggs to be attached to the food-plant by means of some adhesive covering. More striking is the case of certain weevils, which, in order to endow their young with a suitable home, possess the art of rolling a leaf in which the eggs are laid, thus forming a nursery, which serves as board and lodging in one.

Fabre, in a wonderful account of the most skilful of these workers, the Poplar weevil, states that not far from the scroll, made and laboriously rolled by the mother, we almost always find the male. But do not make a mistake. The weevil father is not moved by devotion to the family interests as was the father in the last case we examined. No, rather he is filled with the egoistic desire of the male. But I must give the history as Fabre relates it, fearing to spoil his beautiful account by my own halting description—

“What is he doing there, the idler? Is he watching the work as a mere inquisitive onlooker? From time to time I see him take his stand behind the manufacturer, in the groove of the fold, hang on to a cylinder and join for a little in the work. This is a means of declaring his flame and urging his merits. After several refusals and notwithstanding advances made by a brief collaboration at the scroll, the impatient one is accepted. For ten minutes the rolling is suspended. The male still looks on. Sooner or later a new visit is paid to the worker by the dawdler, who, under pretence of assisting, plants his claws for a moment into the rolling piece, plucks up courage and renews his exploits with the same vigour as though nothing had yet happened. And this is repeated four or five times during the making of a single cigar.”

Here, it may be remarked in passing, we seem to see the first faint expression of the father’s interest in the family, which, if I may hazard a guess, may have started in this way as a means of gaining his desire with the female. The correctness of this surmise will receive considerable confirmation as we proceed with our inquiry. And if analogies with animal conduct were not so apt to be misleading, I would venture to suggest the persistence of the same egoistic factor among many human fathers. But for the present I must leave this question.

From the very beginning of life parental sacrifice is more common in the mother; it is in exceptional cases that her devotion is shared by the father. But such good fathers are of special importance to our inquiry. Even more interesting are those species among which the father takes all charge of the young, while the mother spends her time away from the family. Nor is this departure from what we may call the normal order of the family so surprising as at first sight it may seem, if we can account for the necessity under which probably it arose and seek to explain it.