From an early period of the life-history of our planet, the preservation of the species had obviously become quite as imperative an end as the preservation of individuals; one is at first inclined to say more imperative, but if we pause long enough to remember that total failure to preserve individuals would be equivalent to immediate extinction of the species, we see that the one requirement is as indispensable as the other. Individuals must be preserved, and the struggle for life is between them; species must be preserved, and in the rivalry those have the best chance in which the offspring are either most redundant in numbers or are best cared for. In plants and animals of all but the higher types, the offspring are spores or seeds, larvæ or spawn, or self-maturing eggs. In the absence of parental care the persistence of the species is ensured by the enormous number of such offspring. A single codfish, in a single season, will lay six million eggs, nearly all of which perish, of course, or else in a few years the ocean could not hold all the codfishes. But the princess in the Arabian tale, who fought with the malignant Jinni, could not for her life pick up all the scattered seeds of the pomegranate; and in like manner of the codfish eggs, one in a million or so escapes and the species is maintained. But in the highest types of animal life in birds and mammals—with their four-chambered hearts, completely arterialized blood, and enhanced consciousness—parental care becomes effective in protecting the offspring, and the excessive production diminishes. With birds, the necessity of maintaining a high temperature for the eggs leads to the building of nests, to a division of labour in the securing of food, to the development of a temporary maternal instinct, and to conjugal alliances which in some birds last for a lifetime. As the eggs become effectively guarded the number diminishes, till instead of millions there are half a dozen. When it comes to her more valuable products, Nature is not such a reckless squanderer after all. So with mammals, for the most part the young are in litters of half a dozen or so; but in Man, with his prolonged and costly infancy parental care reaches its highest development and concentration in rearing children one by one.
From the dawn of life, I need hardly say, all the instincts that have contributed to the preservation of offspring must have been favoured and cultivated by natural selection, and in many cases even in types of life very remote from Humanity, such instincts have prompted to very different actions from such as would flow from the mere instinct of self-preservation. If you thrust your walking-stick into an ant-heap, and watch the wild hurry and confusion that ensues when part of the interior is laid bare, you will see that all the workers are busy in moving the larvæ into places of safety. It is not exactly a maternal instinct, for the workers are not mothers, but it is an altruistic instinct involving acts of self-devotion. So in the case of fish that ascend rivers or bays at spawning time, the actions of the whole shoal are determined by a temporarily predominant instinct that tends towards an altruistic result. In these and lower grades of life there is already something at work besides the mere struggle for life between individuals; there is something more than mere contention and slaughter; there is the effort towards cherishing another life than one's own. In these regions of animate existence we catch glimpses of the cosmic roots of love and self-sacrifice. For the simplest and rudest productions of Nature mere egoism might suffice, but to the achievement of any higher aim some adumbration of altruism was indispensable.
Before such divine things as love and self-sacrifice could spring up from their cosmic roots and put forth their efflorescence, it was necessary that conscious personal relations should become established between mother and infant. We have already observed the critical importance of these relations in the earliest stages of the evolution of human society. We may now add that the relation between mother and child must have furnished the first occasion for the sustained and regular development of the altruistic feelings. The capacity for unselfish devotion called forth in that relation could afterward be utilized in the conduct of individuals not thus related to one another.
Of all kinds of altruism the mother's was no doubt the earliest; it was the derivative source from which all other kinds were by slow degrees developed. In the evolution of these altruistic feelings, therefore,—feelings which are an absolutely indispensable constituent in the process of ethical development,—the first appearance of real maternity was an epoch of most profound interest and importance in the history of life upon the earth.
Now maternity, in the true and full sense of the word, is something which was not realized until a comparatively recent stage of the earth's history. God's highest work is never perfected save in the fulness of time. For countless ages there were parents and offspring before the slow but never aimless or wanton cosmic process had brought into existence the conscious personal relationship between mother and child. Protection of eggs and larvæ scarcely suffices for the evolution of true maternity; the relation of moth to caterpillar is certainly very far from being a prototype of it. What spectacle could be more dreary than that of the Jurassic period, with its lords of creation, the oviparous dinosaurs, crawling or bounding over the land, splashing amid the mighty waters, whizzing bat-like through the air, horrible brutes innumerable, with bulky bodies and tiny brains, clumsy, coarse in fibre, and cold-blooded.
"Dragons of the prime,
That tare each other in their slime."
The remnants of that far-off dismal age have been left behind in great abundance, and from them we can easily reconstruct the loathsome picture of a world of dominating egoism, whose redemption through the evolution of true maternity had not yet effectively begun. For such a world might Caliban's theology indeed seem fitted. Nearly nine tenths of our planet's past life-history, measured in duration, had passed away without achieving any higher result than this,—a fact which for impatient reformers may have in it some crumbs of consolation.
For, though the mills of God grind slowly, the cosmic process was aiming at something better than egoism and dinosaurs, and at some time during the long period of the Chalk deposits there began the tremendous world-wide rivalry between these dragons and the rising class of warm-blooded viviparous mammals which had hitherto played an insignificant part in the world. The very name of this class of animals is taken from the function of motherhood. The offspring of these "mammas" come into the world as recognizable personalities, so far developed that the relation between mother and child begins as a relation of personal affection. The new-born mammal is not an egg nor a caterpillar, but a baby, and the baby's dawning consciousness opens up a narrow horizon of sympathy and tenderness, a horizon of which the expansion shall in due course of ages reveal a new heaven and a new earth. At first the nascent altruism was crude enough, but it must have sufficed to make mutual understanding and cooperation more possible than before; it thus contributed to the advancement of mammalian intelligence, and prepared the way for gregariousness, by and by to culminate in sociality, as already described. In the history of creation the mammals were moderns, equipped with more effective means of ensuring survival than their oviparous antagonists. The development of complete mammality was no sudden thing. Some of the dinosaurs may have been ovoviviparous, like some modern serpents. The Australian duck-bill, a relic of the most ancient incipient mammality, is still oviparous; the opossum and kangaroo preserve the record of a stage when viviparousness was but partially achieved; but with the advent of the placental mammals the break with the old order of things was complete.
The results of the struggle are registered in the Eocene rocks. The ancient world had found its Waterloo. Gone were the dragons who so long had lorded it over both hemispheres,—brontosaurs, iguanodons, plesiosaurs, lælaps, pterodactyls,—all gone; their uncouth brood quite vanished from the earth, and nothing left alive as a reminder, save a few degenerate collateral kin, such as snakes and crocodiles, objects of dread and loathing to higher creatures. Never in the history of our planet has there been a more sweeping victory than that of the mammals, nor has Nature had any further occasion for victories of that sort. The mammal remains the highest type of animal existence, and subsequent progress has been shown in the perfecting of that type where most perfectible.