Chapter 19

If human ethics is truly unrelated to beginnings found in lower nature, something that has arisen by itself from supernature, then we must not use the terms in question except by way of analogy. If, however, nature has been continuous in the working out of every department of human life and human thought through evolution, then the criteria of the righteousness of the acts performed even by an _Amoeba_ may be found to be basic and fundamental for ethical systems of whatever human race or time. This subject remains to be discussed in the final chapter, but it must be clear that we cannot survey the evolutionary process by which social systems have come into being without dealing at the same time with the origin and growth of ethical conduct as such.

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Without leaving the group of one-celled animals typified by _Amoeba_, we find colonies of the most elementary biological nature, where other natural obligations are added to the two of greatest importance. Some species of the bell-animalcule, _Vorticella_, provide characteristic examples of these primitive compound protozoa. Here the assemblage is made up of one-celled individuals essentially similar to one another in structure and in physiological activities; in the latter respect each one of them is like _Amoeba_ as well. They may remain together for a longer or shorter period, or during their whole existence until the time of reproduction. Like the solitary protozoön, each member leads a complete life in and by itself, equivalent to that of every biological unit. It obeys the two great laws already laid down, but in addition it seems to be required to remain with the others for some mutual good. The biological value of the association which imposes this additional obligation may be found perhaps in the fact that a large group is not so readily eaten by an enemy as an individual cell; but it is clearer that the process of reproduction, which consists of the fusion of small "gametes," or nucleated fragments produced by diverse or similar parents, must be greatly facilitated by the occurrence of gamete-forming individuals in one and the same colony. "_To remain together_" is the new duty imposed by nature for the good of all and for the welfare of each member of the group. Some biological advantage accrues to the several components, just as the banding of wolves enables the pack to accomplish something which the single wolf is unable to do, although in the latter case it is not so much a reproductive alliance that is formed as an offensive and defensive union.

One step higher in the scale stands the plant-form called _Volvox_, near the border-line between the one-celled and the many-celled organisms. This aquatic type, about the size of the head of an ordinary pin, is a hollow spherical colony, with a wall composed of closely set cellular components. These elements are not all alike, as in the case of colonial protozoa like _Vorticella_, for they fall into two classes which are distinguished by certain structural and functional characteristics. Most of them are simple feeding individuals which absorb nourishment for themselves primarily, but they pass on their surplus supplies to less favored neighbors if occasion demands. The other members begin life like the first-named, but later they become specialized to serve as reproductive individuals solely. Every member of the colony must obey the first precept of nature, otherwise it would be unable to play its part in the life of the whole community. But the discharge of the second natural obligation, namely to preserve the race, is here assigned to some, and to some only, of the whole group of cell individuals. It follows therefore that the division of the tasks necessary for the maintenance of a complete biological individual, and the differentiation of the members of the group into two kinds, leads to the establishment of an individuality of a higher order than the cell. Neither the purely nutritive nor the reproducing member is complete in itself; the two kinds must be combined to make a perfect organism. The life of any member can be selfish no longer, for if it is to exist itself, it must help others for the mutual advantage of all. A clear social relation is thus established; and the reflex conduct of the units of a _Volvox_ colony can be justly denoted altruistic, even though in this case, as before, there can be no conscious recognition of the reasons why mutual interests are best served by what is actually done.

One of the most interesting and significant aspects of the life-history of _Volvox_ is the appearance for the first time of biological death. More elementary organisms are immortal potentially even if not actually, for every portion of the body is capable of passing over into an animal of a succeeding generation. But in _Volvox_ a division of labor has been effected of such a nature that most of the components discharge the tasks of individual value, and with the performance of these they die. Only the reproductive members are immortal in the sense that _Amoeba_ is, for they only have a place in the chain of consecutive generations of _Volvox_ colonies. From the standpoint of the nutritive individual it is better to be relieved of the reproductive task in order that there may be no interruption of its specialized activities for the good of all, but the entailed mortality is certainly disadvantageous to it. It is the higher interest of the colony as a whole that supersedes the welfare of the parts taken singly, and this larger welfare is safeguarded by a differentiation worked out by natural evolution which results in the assignment of personal and racial duties to different individuals, at the cost ultimately of the lives of the former.

We now reach the realm of the true many-celled animals, or Metazoa, where the biological units are combined to form an organic association displaying many more resemblances to a human society. The freshwater polyp _Hydra_, like the foregoing illustrations, is one whose structure has already been discussed in the earlier chapters, but now we may use it for an analysis of another series of biological phenomena. Its sac-like body consists of two cell-layers; the outer one is concerned primarily with offense and defense, while the inner layer is made up of digesting or nutritive elements. The essential cells concerned solely with reproduction lie below the outer sheet. Comparing this animal with an association like _Volvox_, we discover the same differentiation into immortal germ-elements and mortal cells, concerned respectively with the _Hydra's_ racial existence and with its individual life; but far-reaching changes have come about in the biological relationships of the second class of cells. In describing the new phenomena it is absolutely necessary to employ the terms of human social organization, because the _Hydra's_ body is a true colony of diverse cells in exactly the same sense that a nation is a body of human beings with more or less dissimilar social functions.

To begin with the differentiation into ectoderm and endoderm, the organism is comparable to a human community made up of military and agricultural classes. The cells of the former group protect themselves and the feeding elements also, while the units of the second defenseless type devote themselves to the task of provisioning the whole community, giving supplies of food to the defenders in exchange for the protection they afford; each kind needs the other, and each performs some distinctive task for the other as well as for itself. But the parallel thus drawn need not stop here. In the case of the outer layer, the cells are mostly flat covering elements that are the first to be torn off and injured when the animal is attacked. Scattered about among them are sense-cells standing like sentinels with delicate upright processes which receive stimuli from without the sense-cells transmit impulses to the network of nerve-cells below, which is a counterpart of the signal corps of an army, keeping all parts of the whole organization in communication with one another. Most wonderful of all are the stinging-cells of the outer layer; these produce a flask-shaped, poisoned bomb which is discharged by the convulsive contraction of the cell itself so as to stun and injure the enemy or prey. The bomb-throwing cells die immediately after they have ejected their missiles; like soldiers participating in a forlorn hope, they sacrifice their lives in one supreme effort of service to the cell-community of which they are members.

These and similar facts prove conclusively that _Hydra_ is a true community even in the human sense, and that the laws of biological association are established at a point far below the level of the insects. The individuality of the unit is still maintained, and each cell must guard its own interests to a certain degree, but the original independence of the unit has become so altered by differentiation and division of labor that a close interdependent relation has come about. The complete individual is now the _whole_ aggregate; it is the entire _Hydra_ itself which must obey the primary commands of nature to live efficiently and to perpetuate its kind. True it is that the life of the higher individual is the sum total of the activities performed by its constituent cells, but no one of the varied specialized elements is biologically perfect by itself or equivalent to the whole. And, as we have seen, the welfare of the complete animal takes precedence over that of any one of its parts, just as the existence of a nation may be preserved only by the death of soldiers warring for its honor and life.

If, now, we should pass on to the more complex organisms like worms and insects and vertebrates, and should disregard the communal relations of some of these animals, each individual proves to be like _Hydra_ as regards the principles underlying its make-up and workings. A single bee, like a man, is a definitely constituted aggregate of cells, differing as a whole from _Hydra_ only in the _degree of differentiation_ exhibited by its constituent elements. Instead of a loose network of nerve-cells there is the far more complex nervous system whose evolution has been outlined in the sixth chapter. The blood-vascular and respiratory and excretory systems have become well organized, in response, so to speak, to the demands on the part of the nervous and alimentary organs that they may be relieved of the tasks of circulation and respiration and the discharge of ash-wastes. Therefore the cells which make up an insect and a man are more diverse, they have more varied interrelationships, and they are far more interdependent then in the case of the components of _Hydra_. Yet all the many-celled organisms that we are so accustomed to regard as individuals are really communities, demonstrating the existence and partial antithesis of the great laws of egoism and altruism, which are traceable even down to _Amoeba_ and its like.

So much has been made of the lower kinds of cell-associations because the mind of the layman is unconsciously imbued with the idea that human society is a new thing,--an idea which we now see it is necessary to discard at the outset. Indeed, the cell-association of the _Hydra_ and insect type is a more compact and a more stable kind of community than any group of human individuals worked out by nature toward the present end of the whole scheme of evolution. That is to say, the subordination of cell-interest to cell-group welfare, while it must not go so far as to render the unit incapable of doing its work, is sufficiently advanced to make uncontrolled individualism impossible. Let any class of _Hydra's_ cells, such as the nerve or muscle network, assume to exercise a selfish preeminence or to conduct a "strike," the other classes, like the feeding cells, would not be properly served and they would be unable in consequence to work efficiently for the strikers. The immediate result would be suicidal, for the selfish nerve-class would inevitably suffer through the downfall of the whole social fabric. It is a nicely adjusted equilibrium that is established, where the "equal rights" of all the diverse cells consist in freedom to play a special part in the life of the group, serving other individuals in return for their service. The Golden Rule is a natural law as old as nature; for even in _Hydra's_ life, unconscious discharge of duties to the race, and hence to others, is obligatory. And all these low types of organic associations evolved ages before the rules of human social order were vaguely recognized by the reflective self-consciousness of man, to be formulated as the science of ethics.

The evolution of the wonderfully varied societies found among insects begins with the solitary insect itself, just as this, viewed as a cell-community, originates from one-celled beginnings like _Amoeba_ through progressive evolution in time. The similarity between social insects and human associations is clearer than in the case of a comparison between an example from either group and a cell-community, because the higher forms lack the organic contact of the components which is so prominent a feature in the lower instance. The social bonds are looser and they allow a freer play of the constituents; but nevertheless the same laws that control the activities of the cells making up what we now take as the individual element, command obedience on the part of the interrelated members of an insect community with equal strictness.

A butterfly or a moth is primarily egoistic and unsocial in the ordinary sense during its entire life-history, until the final reproductive act which has a value to the species. The caterpillar larva devotes all of its energies to feeding and growing, unconcerned with the final duties of the moth with which it is connected just as the indifferent unit of a young _Volvox_ colony is related to a reproducing member of the full-grown organism. Now and then, it is true, species like the so-called tent caterpillar are met with where numerous larvæ spin silken communal nests to which they retire at night and in which they remain to molt. The pupa, like the larva, is individualistic and employs its time in producing the final adult form. The mature individual, however, is constructed almost solely for the greater purpose of perpetuating the species. Indeed the larger silkworm moths do not and cannot feed, and their value is only that of a device for keeping the race established. Adult may-flies live only a few minutes, just long enough to provide for the fertilization and deposition of the eggs, although to prepare for these acts the young individuals must have toiled for months; the preparatory time may amount to many years in such a case as the seventeen-year locust. But nature is satisfied, as long as the organic mechanisms obey her double commandment, "Live and grow so as to multiply." Like an _Amoeba_, the solitary insect must be egoistic at first, in order to be altruistic in a racial sense in its last days.

Wasps, bees, and ants provide many familiar examples of colonial organizations that become all the more marvelous on closer acquaintance, on account of their resemblances to human associations on the one hand, and to cell-associations on the other. Their illustrative beauty is enhanced by their wide variety, for they grade from counterparts of highly civilized men down to a savage among insects, such as the strictly solitary digger-wasp, whose instincts served to exemplify the insect type of "mentality" in the discussions of the preceding chapter.

The true communities founded by wasps and hornets must be assigned to a low grade in the scale because they originate during a single season and break up at its end; for this very reason the wasp community is intensely interesting to the student of comparative social evolution. In the spring a solitary female emerges from the crevice where she has hibernated and resumes active life; she feeds for a time to renew her strength and then she constructs a simple nest of mud or masticated wood-pulp. In the first few cells of this nest she deposits her eggs, and when they hatch she herself provides the larvæ with food, but still continues to enlarge the house and to produce more eggs. Thus during the first few weeks of the colony's existence this single individual performs a variety of tasks of racial as well as of purely egoistic value; but as time goes on, a profound change comes about in her activities and in the life of the whole community. The members of the first brood do not grow into counterparts of their mother; they are all sexless "workers" who progressively relieve their parent of the tasks of nest-building and foraging and nursing, so that their mother becomes a "queen" who devotes her entire time to the special reproductive task which she only can perform. We may justly compare the queen to the reproductive organ of _Hydra_, for the values to the life of the species are identical in the two cases, while the various classes of workers are counterparts of such units as the muscle and nerve and nutritive components of the _Hydra_ or any other cell-community individual. Another resemblance between the two is found in the death of all the sexless individuals at the end of the season, when reproducing males and females are finally formed, of whom the fertile queens only survive in their winter hiding places; and again we can discover the cause for biological death in that division of labor which calls upon certain members of the whole community to perform tasks that have no value when once provision has been made for perpetuating the species. Finally the mode by which the colony grows and amplifies is in all respects like the embryonic development of an egg into a _Hydra_, so that we may add the phrase "social embryology" to our vocabulary. The original female is an undifferentiated master of all trades; the small tribe she first establishes is little better off than a horde of savages; but during its seasonal existence the community increases in numbers and complexity until it advances well toward the civilized condition, when each class performs its special task for the good of all.

The bees take us higher in the scale, although many solitary species occur, as well as social forms like the bumblebees where colonies are formed in a single season only to break up with the advent of cold weather. The honeybees, however, establish permanent communities from which swarms may set out during the warm months to become new colonies elsewhere. Many hundreds of bees make up a hive, and they belong to three classes or castes, which differ in structure and social function. The queen is a fertile female, the drones are males, and the workers are stunted and infertile females which take no part in reproduction. In this case the queen never discharges any menial duties, for these are attended to by the workers; she devotes her entire time to laying eggs, which are cared for by her subjects, who act as nurses and guards for the monarch as well. The young workers serve at first as doorkeepers, and only later do they take the field in the search for nectar and pollen, and work as house-builders. Each individual performs its special task for its own benefit and for the weal of all; each possesses an equal right to share in the prosperity of the whole community so long as it acts altruistically as well as egoistically. And just as the welfare of _Hydra_ is superior to that of any one of its constituent cells, so the well-being of a hive of bees may be safeguarded only by the actual sacrifice of some of its members. Should food supplies be inadequate, the superfluous drones are stung to death,--the victims of legalized murder. But more marvelous still is the provision that is said to be made by certain individuals for their own destruction should this become desirable. As every one knows, a reigning queen may leave the hive with many of her subjects and "swarm" in a new locality. When she does this, during the warm months, the workers of the original hive feed some of the female larvæ with richer food, and place these potential queens or princesses in special roomy cells apart from the ordinary brood chambers; one of them soon emerges to become a new sovereign. Let us note in passing how similar this is to the production of new egg-cells in a _Hydra_, when the mature germs of an earlier generation are prepared and discharged. When, now, the colder weather sets in, and the possibility of subsequent swarming is set aside, the reigning queen is allowed by her attendant guards to visit the royal cells, whose occupants she stings to death, thus destroying any possible claimant to her place. And when the royal princess constructs her part of the pupal case, she leaves an aperture so that if and when it should become necessary for the queen to kill her, the sovereign would not injure her sting and be unable to kill the other individuals who might become aspirants for the throne and so precipitate a civil war! As in the case of the self-destructive act on the part of a stinging cell in _Hydra_, altruistic subservience to the interests of the colony can go no farther.

The ants form stable colonies of still higher grades, where the workers are not all alike in general structure, but become more rigidly specialized for the performance of restricted tasks. As before, there is the fundamental differentiation into the sexual "queens" and males, and the sterile workers concerned with the immediate material life of the community. In some species the workers serve as herdsmen, caring for the ant-cattle or aphids, from which they receive minute drops of a sweet juice for food. The aphids are tended on the leaves of various plants during the summer, and are carefully reared and stabled and fed below ground during the winter months. In other species seeds are procured and stored in underground granaries. The leaf-cutters are forms which grow food supplies of fungi in subterranean mushroom gardens; the compost consists of cuttings brought from the leaves of bushes by myriads of workers, whose processions are guarded by larger-headed soldiers of several ranks. In the honey-ants of Colorado and tropical America certain individuals pass their time suspended from the roof of a large nest-chamber, where they receive the sweet juice brought in by the workers. They serve as animated preserve jars, distended sometimes to the size of a grape with the communal stores of food, which they return to the workers when external sources of food may fail. Finally there are the slaveholding species which conduct forays upon the nests of other forms, to procure the young of the latter, which grow up in their captors' nests and serve them as nurses and masons and foragers. So long has this custom been established that some slaveholders are entirely unable to feed themselves, and would die out if their slaves failed to support them.

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Let us pause at this point to summarize the results of the foregoing analysis, in order that we may approach the biological study of human associations with definite and clear conceptions of the fundamental laws controlling living communities of all grades.