CHAPTER II: THE DIVERSE INTERESTS OF THE SPECIES, OF THE PARENTS, AND OF THE OFFSPRING.
§ 275. Among the microscopic Protozoa, there is perpetual spontaneous fission. After a few hours of independent existence, each individual is sacrificed in producing two new individuals, which, severally growing, soon themselves repeat the process. And then from time to time there occurs a still more extreme form of reproductive dissolution. After a period of quiescence the entire body breaks up into germs whence arise a new generation. Here, then, a parental life, extremely brief, disappears absolutely in the lives of progeny.
Animal aggregates of the second order show us sundry ways in which this direct transformation of the parental body into the bodies of offspring takes place; though now, of course, at longer intervals. Among the Cœlenterata, there is the case of certain Medusæ, where the polype-like body of the parent, or quasi-parent, after reaching a certain growth, changes into a series of segments looking like a pile of saucers, each of which in turn swims away and becomes a medusa. In these and allied cases of cyclical generation, it may, however, be held that, as the medusa is the adult form, the body of an unsexual individual is sacrificed in producing these partially-developed sexual individuals. A kindred result is achieved in a different manner among some trematode Entozoa. Evolved far enough to have head, appendages, Edition: current; Page: [607] and alimentary system, a Cercaria presently transforms its internal substance into young Cercariæ substantially like itself; and, eventually bursting, sets them free, severally to pursue the same course. Finally, after two or three generations so produced, complete individuals are formed.
Different in method, but showing us in an equal degree the dissolution of a parent’s body into portions that are to continue the race, is the mode of reproduction in the cestoid Entozoa. A segment of a tape-worm, known as a proglottis in its adult and separated state, has then a life shown only by a feeble power of movement. It has descended from one out of myriads of eggs produced by a preceding tape-worm; and is itself, at the time of becoming an independent individual, nothing more than a receptacle for innumerable eggs. Without limbs, without senses, without even alimentary system, its vitality is scarcely higher than that of a plant; and it dies as soon as its contained masses of ova are matured. Here we have an extreme instance of subordination both of adult and young to the interests of the species.
Ascending now to higher types, let us take a few examples from the Articulata. Many kinds of parasitic crustaceans, such as the Lernea, pass through a brief early stage during which the young individual swims about. Nearly always it then dies; but if it succeeds in fixing itself on a fish, it loses its limbs and senses, and, doing nothing but absorb nutriment from the fish, evolves enormous ovisacs. Budding out from the sides of its body, these by and by greatly exceed its body in bulk: the parental life is lost in producing multitudinous eggs. An instance analogous in result, though different in method, occurs even among insects. Having no higher life than is implied by sucking the juice of the cactus over which it creeps, the female cochineal insect develops, as it approaches maturity, masses of ova which eventually fill its interior; and gradually, as its substance is absorbed by the ova, it dies and leaves the shell of its body as a protective envelope for them: whence issuing, ninety-nine are devoured for one Edition: current; Page: [608] that survives. Among superior insects, along with perhaps an equal sacrifice of young, the sacrifice of adults is less. After a larval stage during which the vital activities are relatively low and the mortality high, there comes, for the one survivor out of hundreds, an active maturity. This, however, is brief—sometimes lasting but for a few days; and after the eggs are laid, life forthwith ceases.
The Vertebrata furnish such further illustrations as are needed. In this class the sacrifice of parental life to the maintenance of the species, is in few if any cases direct. A cod produces above a million eggs, and, surviving, does this year after year; but though the life of the parent is preserved, nine hundred and ninety-nine thousand and more of the progeny have their lives cut short at various stages on the way to maturity. In higher types of the class, producing comparatively few eggs that are better provided for, this sacrifice of the rising generation to the interests of the species is much less; and for the like reason it is much less also in the next highest group of vertebrates, the Amphibia. Passing to Birds, we find preservation of the race secured at a greatly diminished cost to both parents and offspring. The young are so well fostered that out of a small number most grow up; while here perhaps a half, and there perhaps a fourth, reach the reproductive stage. Further, the lives of the parents are but partially subordinated at times when the young are being reared. And then there are long intervals between breeding-seasons, during which the lives of parents are carried on for their own sakes. In the highest class of vertebrates, the Mammalia, regarded as a whole, we see a like general advance in this conciliation of the interests of the species, the parents, and the young; and we also see it within the class itself, on ascending from its lower to its higher types. A small rodent reaches maturity in a few months; and, producing large and frequent broods, soon dies. There is but a short early period during which the female lives for herself, and she mostly loses life before the Edition: current; Page: [609] reproductive age is past: thus having no latter days unburdened by offspring. Turning to the other extreme we find an immense contrast. Between twenty and thirty years of a young elephant’s life passes entirely in individual development and activity. The tax of bearing offspring, relatively few and at long intervals, subordinates in but a moderate degree the life of the adult female. And though our knowledge does not enable us to say how long life lasts after the reproductive age is past, yet, considering that the powers remain adequate for sustentation and self-defence, we may infer that the female elephant usually enjoys a closing series of many years; while the male is throughout life scarcely at all taxed.
§ 276. In yet another way does evolution decrease the sacrifice of individual life to the life of the species. The material cost of reproduction involves an equivalent subtraction from individual development and activity, for which among low types there is no compensation; but as we ascend through higher types we find an increasing compensation in the shape of parental pleasures.
Limiting our illustrations to vertebrate animals, we see that by most fishes and amphibians, the spawn, once deposited, is left to its fate: there is great physical expense, and if no subsequent efforts are entailed, there are also none of the accompanying gratifications. It is otherwise with birds and mammals. While the rearing of offspring entails labour on one or both parents, the parental life, though thereby in one way restricted, is in another way extended; since it has become so moulded to the requirements, that the activities of parenthood are sources of agreeable emotions, just as are the activities which achieve self-sustentation.
When, from the less intelligent of these higher vertebrates which produce many young at short intervals, and have to abandon them at early ages, we ascend to the more intelligent which produce few young at longer intervals, and give them Edition: current; Page: [610] aid for longer pediods; we perceive that, while the rate of juvenile mortality is thus diminished, there results both a lessened physical cost of maintaining the species, and an augmented satisfaction of the affections.
§ 277. Here, then, we have definite measures by which to determine what constitutes advance in the relations of parents to offspring and to one another. In proportion as organisms become higher they are individually less sacrificed to the maintenance of the species; and the implication is that in the highest type of man this sacrifice falls to a minimum.
Commonly, when discussing domestic institutions, the welfare of those immediately concerned is almost exclusively regarded. The goodness or badness of given connexions between men and women, is spoken of as though the effects on the existing adult generation were chiefly to be considered; and, if the effects on the rising generation are taken into account, little if any thought is given to the effects which future generations will experience. This order has, as we see, to be reversed.
Family organizations of this or that kind have first to be judged by the degrees in which they help to preserve the social aggregates they occur in; for, in relation to its component individuals, each social aggregate stands for the species. Mankind survives not through arrangements which refer to it as a whole, but by survival of its separate societies; each of which struggles to maintain its existence in presence of other societies. And survival of the race, achieved through survival of its constituent societies, being the primary requirement, the domestic arrangements most conducive to survival in each society, must be regarded as relatively appropriate.
In so far as it consists with preservation of the society, the next highest end is raising the largest number of healthy offspring from birth to maturity. The qualification does not seem needed; but we shall find evidence that it is Edition: current; Page: [611] needed. Societies, and especially primitive groups, do not always thrive by unchecked increase in their numbers; but, contrariwise, in some cases preserve themselves from extinction at the cost of increased mortality of the young.
After welfare of the social group and welfare of progeny, comes welfare of parents. That form of marital relation must in each case be held the best which, subject to these preceding requirements, furthers most, and burdens least, the lives of adult men and women.
And as a last end to be contemplated comes that furtherance of individual life which we see when the declining years of parents, lengthened and made pleasurable by offspring, also become sources of pleasure to those offspring.
Uniting these propositions, we draw the corollary that the highest constitution of the family is reached when there is such conciliation between the needs of the society and those of its members, old and young, that the mortality between birth and the reproductive age falls to a minimum, while the lives of adults have their subordination to the rearing of children reduced to the smallest possible. The diminution of this subordination takes place in three ways: first, by elongation of that period which precedes reproduction; second, by decrease in the number of offspring borne, as well as by increase of the pleasures taken in the care of them; and third, by lengthening of the life which follows cessation of reproduction.
This ideal of the family suggested by a survey of the sexual and parental relations throughout the organic world, is also the ideal to which comparisons between the lower and the higher stages of human progress point. In savage tribes we find great juvenile mortality: there is commonly more or less infanticide; or there are many early deaths from unfavourable conditions; or there are both. Again, these inferior races are characterized by early maturity and commencing reproduction; implying shortness of that first period during which the individual life is carried on for its own Edition: current; Page: [612] sake. While fertility lasts, the tax, especially on the women, who are also exhausted by drudgeries, is great. The marital and parental relations are sources of pleasures neither so high nor so prolonged as in the civilized races. And then after children have been reared, the remaining life of either sex is brief: often being ended by violence; often by deliberate desertion; and otherwise by rapid decay unchecked by filial care.
We are thus furnished with both a relative standard and an absolute standard by which to estimate domestic institutions in each stage of social progress. While, judging them relatively, by their adaptations to the accompanying social requirements, we may be led to regard as needful in their times and places, arrangements that are repugnant to us; we shall, judging them absolutely, in relation to the most developed types of life, individual and national, find good reasons for reprobating them. For this preliminary survey reveals the fact that the domestic relations which are the highest as ethically considered, are also the highest as considered both biologically and sociologically.*