Chapter III: Society and the Group (1)

I. INTRODUCTION

1. Society, the Community, and the Group

Human nature and the person are products of society. This is the sum and substance of the readings in the preceding chapter. But what, then, is society--this web in which the lives of individuals are so inextricably interwoven, and which seems at the same time so external and in a sense alien to them? From the point of view of common sense, "society" is sometimes conceived as the sum total of social institutions. The family, the church, industry, the state, all taken together, constitute society. In this use of the word, society is identified with social structure, something more or less external to individuals.

In accordance with another customary use of the term, "society" denotes a collection of persons. This is a vaguer notion but it at least identifies society with individuals instead of setting it apart from them. But this definition is manifestly superficial. Society is not a collection of persons in the sense that a brick pile is a collection of bricks. However we may conceive the relation of the parts of society to the whole, society is not a mere physical aggregation and not a mere mathematical or statistical unit.

Various explanations that strike deeper than surface observation have been proposed as solutions for this cardinal problem of the social one and the social many; of the relation of society to the individual. Society has been described as a tool, an instrument, as it were, an extension of the individual organism. The argument runs something like this: The human hand, though indeed a part of the physical organism, may be regarded as an instrument of the body as a whole. If, as by accident it be lost, it is conceivable that a mechanical hand might be substituted for it, which, though not a part of the body, would function for all practical purposes as a hand of flesh and blood. A hoe may be regarded as a highly specialized hand, so also logically, if less figuratively, a plow. So the hand of another person if it does your bidding may be regarded as your instrument, your hand. Language is witness to the fact that employers speak of "the hands" which they "work." Social institutions may likewise be thought of as tools of individuals for accomplishing their purposes. Logically, therefore, society, either as a sum of institutions or as a collection of persons, may be conceived of as a sum total of instrumentalities, extensions of the functions of the human organism which enable individuals to carry on life-activities. From this standpoint society is an immense co-operative concern of mutual services.

This latter is an aspect of society which economists have sought to isolate and study. From this point of view the relations of individuals are conceived as purely external to one another, like that of the plants in a plant community. Co-operation, so far as it exists, is competitive and "free."

In contrast with the view of society which regards social institutions and the community itself as the mere instruments and tools of the individuals who compose it, is that which conceives society as resting upon biological adaptations, that is to say upon instincts, gregariousness, for example, imitation, or like-mindedness. The classic examples of societies based on instinct are the social insects, the well-known bee and the celebrated ant. In human society the family, with its characteristic differences and interdependences of the sexes and the age groups, husband and wife, children and parents, most nearly realizes this description of society. In so far as the organization of society is predetermined by inherited or constitutional differences, as is the case pre-eminently in the so-called animal societies, competition ceases and the relations of its component individuals become, so to speak, internal, and a permanent part of the structure of the group.

The social organization of human beings, on the other hand, the various types of social groups, and the changes which take place in them at different times under varying circumstances, are determined not merely by instincts and by competition but by custom, tradition, public opinion, and contract. In animal societies as herds, flocks, and packs, collective behavior seems obviously to be explained in terms of instinct and emotion. In the case of man, however, instincts are changed into habits; emotions, into sentiments. Furthermore, all these forms of behavior tend to become conventionalized and thus become relatively independent of individuals and of instincts. The behavior of the person is thus eventually controlled by the formal standards which, implicit in the mores, are explicit in the laws. Society now may be defined as the social heritage of _habit and sentiment_, _folkways and mores_, _technique and culture_, all of which are incident or necessary to collective human behavior.

Human society, then, unlike animal society is mainly a social heritage, created in and transmitted by communication. The continuity and life of a society depend upon its success in transmitting from one generation to the next its folkways, mores, technique, and ideals. From the standpoint of collective behavior these cultural traits may all be reduced to the one term "consensus." Society viewed abstractly is an organization of individuals; considered concretely it is a complex of organized habits, sentiments, and social attitudes--in short, consensus.

The terms society, community, and social group are now used by students with a certain difference of emphasis but with very little difference in meaning. Society is the more abstract and inclusive term, and society is made up of social groups, each possessing its own specific type of organization but having at the same time all the general characteristics of society in the abstract. Community is the term which is applied to societies and social groups where they are considered from the point of view of the geographical distribution of the individuals and institutions of which they are composed. It follows that every community is a society, but not every society is a community. An individual may belong to many social groups but he will not ordinarily belong to more than one community, except in so far as a smaller community of which he is a member is included in a larger of which he is also a member. However, an individual is not, at least from a sociological point of view, a member of a community because he lives in it but rather because, and to the extent that, he participates in the common life of the community.

The term social group has come into use with the attempts of students to classify societies. Societies may be classified with reference to the rôle which they play in the organization and life of larger social groups or societies. The internal organization of any given social group will be determined by its external relation to other groups in the society of which it is a part as well as by the relations of individuals within the group to one another. A boys' gang, a girls' clique, a college class, or a neighborhood conforms to this definition quite as much as a labor union, a business enterprise, a political party, or a nation. One advantage of the term "group" lies in the fact that it may be applied to the smallest as well as to the largest forms of human association.

2. Classification of the Materials

Society, in the most inclusive sense of that term, the Great Society, as Graham Wallas described it, turns out upon analysis to be a constellation of other smaller societies, that is to say races, peoples, parties, factions, cliques, clubs, etc. The community, the world-community, on the other hand, which is merely the Great Society viewed from the standpoint of the territorial distribution of its members, presents a different series of social groupings and the Great Society in this aspect exhibits a totally different pattern. From the point of view of the territorial distribution of the individuals that constitute it, the world-community is composed of nations, colonies, spheres of influence, cities, towns, local communities, neighborhoods, and families.

These represent in a rough way the subject-matter of sociological science. Their organization, interrelation, constituent elements, and the characteristic changes (social processes) which take place in them are the phenomena of sociological science.

Human beings as we meet them are mobile entities, variously distributed through geographical space. What is the nature of the connection between individuals which permits them at the same time to preserve their distances and act corporately and consentiently--with a common purpose, in short? These distances which separate individuals are not merely spatial, they are psychical. Society exists where these distances have been _relatively_ overcome. Society exists, in short, not merely where there are people but where there is communication.

The materials in this chapter are intended to show (1) the fundamental character of the relations which have been established between individuals through communication; (2) the gradual evolution of these relations in animal and human societies. On the basis of the principle thus established it is possible to work out a rational classification of social groups.

Espinas defines society in terms of corporate action. Wherever separate individuals act together as a unit, where they co-operate as though they were parts of the same organism, there he finds society. Society from this standpoint is not confined to members of one species, but may be composed of different members of species where there is permanent joint activity. In the study of symbiosis among animals, it is significant to note the presence of structural adaptations in one or both species. In the taming and domestication of animals by man the effects of symbiosis are manifest. Domestication, by the selection in breeding of traits desired by man, changes the original nature of the animal. Taming is achieved by control of habits in transferring to man the filial and gregarious responses of the young naturally given to its parents and members of its kind. Man may be thought of as domesticated through natural social selection. Eugenics is a conscious program of further domestication by the elimination of defective physical and mental racial traits and by the improvement of the racial stock through the social selection of superior traits. Taming has always been a function of human society, but it is dignified by such denominations as "education," "social control," "punishment," and "reformation."

The plant community offers the simplest and least qualified example of the community. Plant life, in fact, offers an illustration of a _community_ which is _not a society_. It is not a society because it is an organization of individuals whose relations, if not wholly external, are, at any rate, "unsocial" in so far as there is no consensus. The plant community is interesting, moreover, because it exhibits in the barest abstraction, the character of _competitive co-operation_, the aspect of social life which constitutes part of the special subject-matter of economic science.

This struggle for existence, in some form or other, is in fact essential to the existence of society. Competition, segregation, and accommodation serve to maintain the social distances, to fix the status, and preserve the independence of the individual in the social relation. A society in which all distances, physical as well as psychical, had been abolished, in which there was neither taboo, prejudice, nor reserve of any sort; a society in which the intimacies were absolute, would be a society in which there were neither persons nor freedom. The processes of competition, segregation, and accommodation brought out in the description of the plant community are quite comparable with the same processes in animal and human communities. A village, town, city, or nation may be studied from the standpoint of the adaptation, struggle for existence, and survival of its individual members in the environment created by the community as a whole.

Society, as Dewey points out, if based on instinct is an effect of communication. _Consensus_ even more than _co-operation_ or _corporate action_ is the distinctive mark of human society. Dewey, however, seems to restrict the use of consensus to group decisions in which all the members consciously and rationally participate. Tradition and sentiment are, however, forms of consensus quite as much as constitutions, rules, and elections.

Le Bon's classification of social groups into heterogeneous and homogeneous crowds, while interesting and suggestive, is clearly inadequate. Many groups familiar to all of us, as the family, the play-group, the neighborhood, the public, find no place in his system.[80]

Concrete descriptions of group behavior indicate three elements in the consensus of the members of the group. The first is the characteristic state of group feeling called _esprit de corps_. The enthusiasm of the two sides in a football contest, the ecstasy of religious ceremonial, the fellowship of members of a fraternity, the brotherhood of a monastic band are all different manifestations of group spirit.

The second element in consensus has become familiar through the term "morale." Morale may be defined as the collective will. Like the will of the individual it represents an organization of behavior tendencies. The discipline of the individual, his subordination to the group, lies in his participation and reglementation in social activities.

The third element of consensus which makes for unified behavior of the members of the group has been analyzed by Durkheim under the term "collective representations." Collective representations are the concepts which embody the objectives of group activity.

The totem of primitive man, the flag of a nation, a religious creed, the number system, and Darwin's theory of the descent of man--all these are collective representations. Every society and every social group has, or tends to have, its own symbols and its own language. The language and other symbolic devices by which a society carries on its collective existence are collective representations. Animals do not possess them.

II. MATERIALS

A. SOCIETY AND SYMBIOSIS

1. Definition of Society[81]

The idea of society is that of a permanent co-operation in which separate living beings undertake to accomplish an identical act. These beings may find themselves brought by their conditions to a point where their co-operation forces them to group themselves in space in some definite form, but it is by no means necessary that they should be in juxtaposition for them to act together and thus to form a society. A customary reciprocation of services among more or less independent individualities is the characteristic feature of the social life, a feature that contact or remoteness does not essentially modify, nor the apparent disorder nor the regular disposition of the parties in space.

Two beings may then form what is to the eyes a single mass, and may live, not only in contact with each other, but even in a state of mutual penetration without constituting a society. It is enough in such a case that one looks at them as entirely distinct, that their activities tend to opposite or merely different ends. If their functions, instead of co-operating, diverge; if the good of one is the evil of the other, whatever the intimacy of their contact may be, no social bond unites them.

But the nature of the functions and the form of the organs are inseparable. If two beings are endowed with functions that necessarily combine, they are also endowed with organs, if not similar, at least corresponding. And these beings with like or corresponding organs are either of the same species or of very nearly the same species.

However, circumstances may be met where two beings with quite different organs and belonging even to widely remote species may be accidentally and at a single point useful to each other. A habitual relation may be established between their activities, but only on this one point, and in the time limits in which the usefulness exists. Such a case gives the occasion, if not for a society, at least for an association; that is to say, a union less necessary, less strict, less durable, may find its origin in such a meeting. In other words, beside the normal societies formed of elements specifically alike, which cannot exist without each other, there will be room for more accidental groupings, formed of elements more or less specifically unlike, which convenience unites and not necessity. We will commence with a study of the latter.

To society the most alien relations of two living beings which can be produced are those of the predator and his prey. In general, the predator is bulkier than his prey, since he overcomes him and devours him. Yet smaller ones sometimes attack larger creatures, consuming them, however, by instalments, and letting them live that they themselves may live on them as long as possible. In such a case they are forced to remain for a longer or a shorter time attached to the body of their victim, carried about by it wherever the vicissitudes of its life lead them. Such animals have received the name of parasites. Parasitism forms the line inside of which our subject begins; for if one can imagine that the parasite, instead of feeding on the animal from whom he draws his subsistence, is content to live on the remains of the other's meals, one will find himself in the presence, not yet of an actual society, but of half the conditions of a society; that is to say, a relation between two beings such that, all antagonism ceasing, one of the two is useful to the other. Such is commensalism. However, this association does not yet offer the essential element of all society, co-operation. There is co-operation when the commensal is not less useful to his host than the latter is to the commensal himself, when the two are concerned in living in a reciprocal relation and in developing their double activity in corresponding ways toward a single and an identical goal. One has given to this mode of activity the name of mutualism. Domestication is only one form of it. Parasitism, commensalism, mutualism, exist with animals among the different species.

2. Symbiosis (literally "living together")[82]

In gaining their wide and intimate acquaintance with the vegetable world the ants have also become acquainted with a large number of insects that obtain their nutriment directly from plants, either by sucking up their juices or by feeding on their foliage. To the former group belong the phytophthorous Homoptera, the plant lice, scale insects, or mealy bugs, tree-hoppers, lantern flies, and jumping plant lice; to the latter belong the caterpillars of the lycaenid butterflies, the "blues," or "azures," as they are popularly called. All of these creatures excrete liquids which are eagerly sought by the ants and constitute the whole, or, at any rate, an important part of the food of certain species. In return the Homoptera and caterpillars receive certain services from the ants, so that the relations thus established between these widely different insects may be regarded as a kind of symbiosis. These relations are most apparent in the case of the aphids, and these insects have been more often and more closely studied in Europe and America.

The consociation of the ants with the aphids is greatly facilitated by the gregarious and rather sedentary habits of the latter, especially in their younger, wingless stages, for the ants are thus enabled to obtain a large amount of food without losing time and energy in ranging far afield from their nests. Then, too, the ants may establish their nests in the immediate vicinity of the aphid droves or actually keep them in their nests or in "sheds" carefully constructed for the purpose.

Some ants obtain the honey-dew merely by licking the surface of the leaves and stems on which it has fallen, but many species have learned to stroke the aphids and induce them to void the liquid gradually so that it can be imbibed directly. A drove of plant lice, especially when it is stationed on young and succulent leaves or twigs, may produce enough honey-dew to feed a whole colony of ants for a considerable period.

As the relations between ants and the various Homoptera have been regarded as mutualistic, it may be well to marshal the facts which seem to warrant this interpretation. The term "mutualism" as applied to these cases means, of course, that the aphids, coccids, and membracids are of service to the ants and in turn profit by the companionship of these more active and aggressive insects. Among the modifications in structure and behavior which may be regarded as indicating on the part of aphids unmistakable evidence of adaptation to living with ants, the following may be cited:

1. The aphids do not attempt to escape from the ants or to defend themselves with their siphons, but accept the presence of these attendants as a matter of course.

2. The aphids respond to the solicitations of the ants by extruding the droplets of honey-dew gradually and not by throwing them off to a distance with a sudden jerk, as they do in the absence of ants.

3. Many species of Aphididae that live habitually with ants have developed a perianal circlet of stiff hairs which support the drop of honey-dew till it can be imbibed by the ants. This circlet is lacking in aphids that are rarely or never visited by ants.

4. Certain observations go to show that aphids, when visited by ants, extract more of the plant juices than when unattended.

The adaptations on the part of the ants are, with a single doubtful exception, all modifications in behavior and not in structure.

1. Ants do not seize and kill aphids as they do when they encounter other sedentary defenseless insects.

2. The ants stroke the aphids in a particular manner in order to make them excrete the honey-dew, and know exactly where to expect the evacuated liquid.

3. The ants protect the aphids. Several observers have seen the ants driving away predatory insects.

4. Many aphidicolous ants, when disturbed, at once seize and carry their charges in their mandibles to a place of safety, showing very plainly their sense of ownership and interest in these helpless creatures.

5. This is also exhibited by all ants that harbor root-aphids and root-coccids in their nests. Not only are these insects kept in confinement by the ants, but they are placed by them on the roots. In order to do this the ants remove the earth from the surfaces of the roots and construct galleries and chambers around them so that the Homoptera may have easy access to their food and even move about at will.

6. Many ants construct, often at some distance from their nests, little closed pavilions or sheds of earth, carton, or silk, as a protection for their cattle and for themselves. The singular habit may be merely a more recent development from the older and more general habit of excavating tunnels and chambers about roots and subterranean stems.

7. The solicitude of the ants not only envelops the adult aphids and coccids, but extends also to their eggs and young. Numerous observers have observed ants in the autumn collecting and storing aphid eggs in the chambers of their nests, caring for them through the winter and in the spring placing the recently hatched plant lice on the stems and roots of the plants.

In the foregoing I have discussed the ethological relations of ants to a variety of other organisms. This, however, did not include an account of some of the most interesting symbiotic relations, namely, those of the ants to other species of their own taxonomic group and to termites. This living together of colonies of different species may be properly designated as social symbiosis, to distinguish it from the simple symbiosis that obtains between individual organisms of different species and the intermediate form of symbiosis exhibited by individual organisms that live in ant or termite colonies.

The researches of the past forty years have brought to light a remarkable array of instances of social symbiosis, varying so much in intimacy and complexity that it is possible to construct a series ranging from mere simultaneous occupancy of a very narrow ethological station, or mere contiguity of domicile, to an actual fusion, involving the vital dependence or parasitism of a colony of one species on that of another. Such a series is, of course, purely conceptual and does not represent the actual course of development in nature, where, as in the animal and vegetable kingdoms in general, development has not followed a simple linear course, but has branched out repeatedly and terminated in the varied types at the present time.

It is convenient to follow the European writers, von Hagens, Forel, Wasmann, and others, in grouping all the cases of social symbiosis under two heads, the compound nests and the mixed colonies. Different species of ants or of ants and termites are said to form compound nests when their galleries are merely contiguous or actually interpenetrate and open into one another, although the colonies which inhabit them bring up their respective offspring in different apartments. In mixed colonies, on the other hand, which, in a state of nature, can be formed only by species of ants of close taxonomic affinities, the insects live together in a single nest and bring up their young in common. Although each of these categories comprises a number of dissimilar types of social symbiosis, and although it is possible, under certain circumstances, as will be shown in the sequel, to convert a compound nest into a mixed colony, the distinction is nevertheless fundamental. It must be admitted, however, that both types depend in last analysis on the dependent, adoption-seeking instincts of the queen ant and on the remarkable plasticity which enables allied species and genera to live in very close proximity to one another. By a strange paradox these peculiarities have been produced in the struggle for existence, although this struggle is severer among different species of ants than between ants and other organisms. As Forel says: "The greatest enemies of ants are other ants, just as the greatest enemies of men are other men."

3. The Taming and the Domestication of Animals[83]

Primitive man was a hunter almost before he had the intelligence to use weapons, and from the earliest times he must have learned something about the habits of the wild animals he pursued for food or for pleasure, or from which he had to escape. It was probably as a hunter that he first came to adopt young animals which he found in the woods or the plains, and made the surprising discovery that these were willing to remain under his protection and were pleasing and useful. He passed gradually from being a hunter to becoming a keeper of flocks and herds. From these early days to the present time, the human race has taken an interest in the lower animals, and yet extremely few have been really domesticated. The living world would seem to offer an almost unlimited range of creatures which might be turned to our profit and as domesticated animals minister to our comfort or convenience. And yet it seems as if there were some obstacle rooted in the nature of animals or in the powers of man, for the date of the adoption by man of the few domesticated species lies in remote, prehistoric antiquity. The surface of the earth has been explored, the physiology of breeding and feeding has been studied, our knowledge of the animal kingdom has been vastly increased, and yet there is hardly a beast bred in the farm-yard today with which the men who made stone weapons were not acquainted and which they had not tamed. Most of the domestic animals of Europe, America, and Asia came originally from Central Asia, and have spread thence in charge of their masters, the primitive hunters who captured them.

No monkeys have been domesticated. Of the carnivores only the cat and the dog are truly domesticated. Of the ungulates there are horses and asses, pigs, cattle, sheep, goats, and reindeer. Among rodents there are rabbits and guinea-pigs, and possibly some of the fancy breeds of rats and mice should be included. Among birds there are pigeons, fowls, peacocks, and guinea-fowl, and aquatic birds such as swans, geese, and ducks, whilst the only really domesticated passerine bird is the canary. Goldfish are domesticated, and the invertebrate bees and silk-moths must not be forgotten. It is not very easy to draw a line between domesticated animals and animals that are often bred in partial or complete captivity. Such antelopes as elands, fallow-deer, roe-deer, and the ostriches of ostrich farms are on the border-line of being domesticated.

It is also difficult to be quite certain as to what is meant by a tame animal. Cockroaches usually scuttle away when they are disturbed and seem to have learnt that human beings have a just grievance against them. But many people have no horror of them. A pretty girl, clean and dainty in her ways, and devoted to all kinds of animals, used to like sitting in a kitchen that was infested with these repulsive creatures, and told me that when she was alone they would run over her dress and were not in the least startled when she took them up. I have heard of a butterfly which used to come and sip sugar from the hand of a lady; and those who have kept spiders and ants declare that these intelligent creatures learn to distinguish their friends. So also fish, like the great carp in the garden of the palace of Fontainebleau, and many fishes in aquaria and private ponds, learn to come to be fed. I do not think, however, that these ought to be called tame animals. Most of the wild animals in menageries very quickly learn to distinguish one person from another, to obey the call of their keeper and to come to be fed, although certainly they would be dangerous even to the keeper if he were to enter their cages. To my mind, tameness is something more than merely coming to be fed, and, in fact, many tame animals are least tame when they are feeding. Young carnivores, for instance, which can be handled freely and are affectionate, very seldom can be touched whilst they are feeding. The real quality of tameness is that the tame animal is not merely tolerant of the presence of man, not merely has learned to associate him with food, but takes some kind of pleasure in human company and shows some kind of affection.

On the other hand, we must not take our idea of tameness merely from the domesticated animals. These have been bred for many generations, and those that were most wild and that showed any resistance to man were killed or allowed to escape. Dogs are always taken as the supreme example of tameness, and sentimentalists have almost exhausted the resources of language in praising them. Like most people, I am very fond of dogs, but it is an affection without respect. Dogs breed freely in captivity, and in the enormous period of time that has elapsed since the first hunters adopted wild puppies there has been a constant selection by man, and every dog that showed any independence of spirit has been killed off. Man has tried to produce a purely subservient creature, and has succeeded in his task. No doubt a dog is faithful and affectionate, but he would be shot or drowned or ordered to be destroyed by the local magistrate if he were otherwise. A small vestige of the original spirit has been left in him, merely from the ambition of his owners to possess an animal that will not bite them, but will bite anyone else. And even this watch-dog trait is mechanical, for the guardian of the house will worry the harmless, necessary postman, and welcome the bold burglar with fawning delight. The dog is a slave, and the crowning evidence of his docility, that he will fawn on the person who has beaten him, is the result of his character having been bred out of him. The dog is an engaging companion, an animated toy more diverting than the cleverest piece of clockwork, but it is only our colossal vanity that makes us take credit for the affection and faithfulness of our own particular animal. The poor beast cannot help it; all else has been bred out of him generations ago.

When wild animals become tame, they are really extending or transferring to human beings the confidence and affection they naturally give their mothers, and this view will be found to explain more facts about tameness than any other. Every creature that would naturally enjoy maternal, or it would be better to say parental, care, as the father sometimes shares in or takes upon himself the duty of guarding the young, is ready to transfer its devotion to other animals or to human beings, if the way be made easy for it, and if it be treated without too great violation of its natural instincts. The capacity to be tamed is greatest in those animals that remain longest with their parents and that are most intimately associated with them. The capacity to learn new habits is greatest in those animals which naturally learn most from their parents, and in which the period of youth is not merely a period of growing, a period of the awakening of instincts, but a time in which a real education takes place. These capacities of being tamed and of learning new habits are greater in the higher mammals than in the lower mammals, in mammals than in birds, and in birds than in reptiles. They are very much greater in very young animals, where dependence on the parents is greatest, than in older animals, and they gradually fade away as the animal grows up, and are least of all in fully grown and independent creatures of high intelligence.

Young animals born in captivity are no more easy to tame than those which have been taken from the mother in her native haunts. If they remain with the mother, they very often grow up even shyer and more intolerant of man than the mothers themselves. There is no inherited docility or tameness, and a general survey of the facts fully bears out my belief that the process of taming is almost entirely a transference to human beings of the confidence and affection that a young animal would naturally give its mother. The process of domestication is different, and requires breeding a race of animals in captivity for many generations and gradually weeding out those in which youthful tameness is replaced by the wild instinct of adult life, and so creating a strain with new and abnormal instincts.

B. PLANT COMMUNITIES AND ANIMAL SOCIETIES

1. Plant Communities[84]

Certain species group themselves into natural associations, that is to say, into communities which we meet with more or less frequently and which exhibit the same combination of growth-forms and the same facies. As examples in northern Europe may be cited a meadow with its grasses and perennial herbs, or a beech forest with its beech trees and all the species usually accompanying these. Species that form a community must either practice the same economy, making approximately the same demands on its environment (as regards nourishment, light, moisture, and so forth), or one species present must be dependent for its existence upon another species, sometimes to such an extent that the latter provides it with what is necessary or even best suited to it (Oxalis Acetosella and saprophytes which profit from the shade of the beech and from its humus soil); a kind of symbiosis seems to prevail between such species. In fact, one often finds, as in beech forests, that the plants growing under the shade and protection of other species, and belonging to the most diverse families, assume growth-forms that are very similar to one another, but essentially different from those of the forest trees, which, in their turn, often agree with one another.

The ecological analysis of a plant-community leads to the recognition of the growth-forms composing it as its ultimate units. From what has just been said in regard to growth-forms it follows that species of very diverse physiognomy can very easily occur together in the same natural community. But beyond this, as already indicated, species differing widely, not only in physiognomy but also in their whole economy, may be associated. We may therefore expect to find both great variety of form and complexity of interrelations among the species composing a natural community; as an example we may cite the richest of all types of communities--the tropical rain-forest. It may also be noted that the physiognomy of a community is not necessarily the same at all times of the year, the distinction sometimes being caused by a rotation of species.

The different communities, it need hardly be stated, are scarcely ever sharply marked off from one another. Just as soil, moisture, and other external conditions are connected by the most gradual transitions, so likewise are the plant-communities, especially in cultivated lands. In addition, the same species often occur in several widely different communities; for example, Linnaea borealis grows not only in coniferous forests, but also in birch woods, and even high above the tree limit on the mountains of Norway and on the fell-fields of Greenland. It appears that different combinations of external factors can replace one another and bring into existence approximately the same community, or at least can satisfy equally well one and the same species, and that, for instance, a moist climate often completely replaces the forest shade of dry climates.

The term "community" implies a diversity but at the same time a certain organized uniformity in the units. The units are the many individual plants that occur in every community, whether this be a beech forest, a meadow, or a heath. Uniformity is established when certain atmospheric, terrestrial, and other factors are co-operative, and appears either because a certain defined economy makes its impress on the community as a whole, or because a number of different growth-forms are combined to form a single aggregate which has a definite and constant guise.

The analysis of a plant-community usually reveals one or more of the kinds of symbiosis as illustrated by parasites, saprophytes, epiphytes, and the like. There is scarce a forest or a bushland where examples of these forms of symbiosis are lacking; if, for instance, we investigate the tropical rain-forest we are certain to find in it all conceivable kinds of symbiosis. But the majority of individuals of a plant-community are linked by bonds other than those mentioned--bonds that are best described as _commensal_. The term _commensalism_ is due to Van Beneden, who wrote, "Le commensal est simplement un compagnon de table"; but we employ it in a somewhat different sense to denote the relationship subsisting between species which share with one another the supply of food-material contained in soil and air, and thus feed at the same table.

More detailed analysis of the plant-community reveals very considerable distinctions among commensals. Some relationships are considered in the succeeding paragraphs.

_Like commensals._--When a plant-community consists solely of individuals belonging to one species--for example, solely of beech, ling, or Aira flexuosa--then we have the purest example of like commensals. These all make the same demands as regards nutriment, soil, light, and other like conditions; as each species requires a certain amount of space and as there is scarcely ever sufficient nutriment for all the offspring, a struggle for food arises among the plants so soon as the space is occupied by the definite numbers of individuals which, according to the species, can develop thereon. The individuals lodged in unfavorable places and the weaklings are vanquished and exterminated. This competitive struggle takes place in all plant-communities, with perhaps the sole exceptions of sub-glacial communities and in deserts. In these _open communities_ the soil is very often or always so open and so irregularly clothed that there is space for many more individuals than are actually present; the cause for this is obviously to be sought in the climatically unfavorable conditions of life, which either prevent plants from producing seed and other propagative bodies in sufficient numbers to clothe the ground or prevent the development of seedlings. On such soil one can scarcely speak of a competitive struggle for existence; in this case a struggle takes place between the plant and inanimate nature, but to little or no extent between plant and plant.

That a congregation of individuals belonging to one species into one community may be profitable to the species is evident; it may obviously in several ways aid in maintaining the existence of the species, for instance, by facilitating abundant and certain fertilization (especially in anemophilous plants) and maturation of seeds; in addition, the social mode of existence may confer other less-known advantages. But, on the other hand, it brings with it greater danger of serious damage and devastation wrought by parasites.

The bonds that hold like individuals to a like habitat are, as already indicated, identical demands as regards existence, and these demands are satisfied in their precise habitat to such an extent that the species can maintain itself here against rivals. Natural unmixed associations of forest trees are the result of struggles with other species. But there are differences as regards the ease with which a community can arise and establish itself. Some species are more social than others, that is to say, better fitted to form communities. The causes for this are biological, in that some species, like Phragmites, Scirpus lacustris, Psamma (Ammophila) arenaria, Tussilago, Farfara, and Asperula odorata, multiply very readily by means of stolons; or others, such as Cirsium arvense, and Sonchus arvensis, produce buds from their roots; or yet others produce numerous seeds which are easily dispersed and may remain for a long time capable of germinating, as is the case with Calluna, Picea excelsa, and Pinus; or still other species, such as beech and spruce, have the power of enduring shade or even suppressing other species by the shade they cast. A number of species, such as Pteris aquilina, Acorus Calamus, Lemna minor, and Hypnum Schreberi, which are social, and likewise very widely distributed, multiply nearly exclusively by vegetative means, rarely or never producing fruit. On the contrary, certain species, for example, many orchids and Umbelliferae, nearly always grow singly.

In the case of many species certain geological conditions have favored their grouping together into pure communities. The forests of northern Europe are composed of few species, and are not mixed in the same sense as are those in the tropics, or even those in Austria and other southern parts of Europe: the cause for this may be that the soil is geologically very recent, inasmuch as the time that has elapsed since the glacial epoch swept it clear has been too short to permit the immigration of many competitive species.

_Unlike commensals._--The case of a community consisting of individuals belonging to one species is, strictly speaking, scarcely ever met with; but the dominant individuals of a community may belong to a single species, as in the case of a beech forest, spruce forest, or ling heath--and only thus far does the case proceed. In general, many species grow side by side, and many different growth-forms and types of symbiosis, in the extended sense, are found collected in a community. For even when one species occupies an area as completely as the nature of the soil will permit, other species can find room and can grow between its individuals; in fact, if the soil is to be completely covered the vegetation must necessarily always be heterogeneous. The greatest aggregate of existence arises where the greatest diversity prevails. The kind of communal life resulting will depend upon the nature of the demands made by the species in regard to conditions of life. As in human communities, so in this case, the _struggle between the like_ is the _most severe_, that is, between the species making more or less the same demands and wanting the same dishes from the common table. In a tropical mixed forest there are hundreds of species of trees growing together in such profuse variety that the eye can scarce see at one time two individuals of the same species, yet all of them undoubtedly represent tolerable uniformity in the demands they make as regards conditions of life, and in so far they are alike. And among them a severe competition for food must be taking place. In those cases in which certain species readily grow in each other's company--and cases of this kind are familiar to florists--when, for instance, Isoetes, Lobelia Dortmanna, and Litorella lacustris occur together--the common demands made as regards external conditions obviously form the bond that unites them. Between such species a competitive struggle must take place. Which of the species shall be represented by the greatest number of individuals certainly often depends upon casual conditions, a slight change in one direction or the other doubtless often playing a decisive rôle; but apart from this it appears that morphological and biological features, for example, development at a different season, may change the nature of the competition.

Yet there are in every plant-community numerous species which _differ widely_ in the demands they make for light, heat, nutriment, and so on. Between such species there is less competition, the greater the disparity in their wants; the case is quite conceivable in which the _one species should require exactly what the other would avoid_; the two species would then be complementary to one another in their occupation and utilization of the same soil.

There are also obvious cases in which different species are of service to each other. The carpet of moss in a pine forest, for example, protects the soil from desiccation and is thus useful to the pine; yet, on the other hand, it profits from the shade cast by the latter.

As a rule, limited numbers of definite species are the most potent, and, like absolute monarchs, can hold sway over the whole area; while other species, though possibly present in far greater numbers than these, are subordinate or even dependent on them. This is the case where subordinate species only flourish in the shade or among the fallen fragments of dominant species. Such is obviously the relationship between trees and many plants growing on the ground of high forest, such as mosses, fungi, and other saprophytes, ferns, Oxalis Acetosella, and their associates. In this case, then, there is a commensalism in which individuals feed at the same table but on different fare. An additional factor steps in when species do not absorb their nutriment at the same season of the year. Many spring plants--for instance, Galanthus nivalis, Corydalis solida, and C. cava--have withered before the summer plants commence properly to develop. Certain species of animals are likewise confined to certain plant-communities. But one and the same tall plant may, in different places or soils, have different species of lowly plants as companions; the companion plants of high beech forests depend, for instance, upon climate and upon the nature of the forest soil; Pinus nigra, according to von Beck, can maintain under it in the different parts of Europe a Pontic, a central European, or a Baltic vegetation.

There are certain points of resemblance between communities of plants and those of human beings or animals; one of these is the competition for food which takes place between similar individuals and causes the weaker to be more or less suppressed. But far greater are the distinctions. The plant-community is the lowest form; it is merely a congregation of units, among which there is no co-operation for the common weal, but rather a ceaseless struggle of all against all. Only in a loose sense can we speak of certain individuals protecting others, as for example, when the outermost and most exposed individuals of scrub serve to shelter from the wind others, which consequently become taller and finer; for they do not afford protection from any special motive, such as is met with in some animal communities, nor are they in any way specially adapted to act as guardians against a common foe. In the plant-community egoism reigns supreme. The plant-community has no higher units or personages in the sense employed in connection with human communities, which have their own organizations and their members co-operating, as prescribed by law, for the common good. In plant-communities there is, it is true, often (or always) a certain natural dependence or reciprocal influence of many species upon one another; they give rise to definite organized units of a higher order; but there is no thorough or organized division of labor such as is met with in human and animal communities, where certain individuals or groups of individuals work as organs, in the wide sense of the term, for the benefit of the whole community.

Woodhead has suggested the term _complementary association_ to denote a community of species that live together in harmony, because their rhizomes occupy different depths in the soil; for example, he described an "association" in which Holcus mollis is the "surface plant," Pteris aquilina has deeper-seated rhizomes, and Scilla festalis buries its bulbs at the greatest depth. The photophilous parts of these plants are "seasonably complementary." The opposite extreme is provided by _competitive associations_, composed of species that are battling with each other.

2. Ant Society[85]

There is certainly a striking parallelism between the development of human and ant societies. Some anthropologists, like Topinard, distinguish in the development of human societies six different types or stages, designated as the hunting, pastoral, agricultural, commercial, industrial, and intellectual. The ants show stages corresponding to the first three of these, as Lubbock has remarked.

Some species, such as _Formica fusca_, live principally on the
produce of the chase; for though they feed partially on the
honey-dew of aphids, they have not domesticated these insects.
These ants probably retain the habits once common to all ants.
They resemble the lower races of men, who subsist mainly by
hunting. Like them they frequent woods and wilds, live in
comparatively small communities, as the instincts of collective
action are but little developed among them. They hunt singly,
and their battles are single combats, like those of Homeric
heroes. Such species as _Lasius flavus_ represent a distinctly
higher type of social life; they show more skill in
architecture, may literally be said to have domesticated
certain species of aphids, and may be compared to the pastoral
stage of human progress--to the races which live on the
products of their flocks and herds. Their communities are more
numerous; they act much more in concert; their battles are not
mere single combats, but they know how to act in combination. I
am disposed to hazard the conjecture that they will gradually
exterminate the mere hunting species, just as savages disappear
before more advanced races. Lastly, the agricultural nations
may be compared with the harvesting ants.

Granting the resemblances above mentioned between ant and human societies, there are nevertheless three far-reaching differences between insect and human organization and development to be constantly borne in mind:

a) Ant societies are societies of females. The males really take no part in the colonial activities, and in most species are present in the nest only for the brief period requisite to secure the impregnation of the young queens. The males take no part in building, provisioning, or guarding the nest or in feeding the workers or the brood. They are in every sense the _sexus sequior_. Hence the ants resemble certain mythical human societies like the Amazons, but unlike these, all their activities center in the multiplication and care of the coming generations.

b) In human society, apart from the functions depending on sexual dimorphism, and barring individual differences and deficiencies which can be partially or wholly suppressed, equalized, or augmented by an elaborate system of education, all individuals have the same natural endowment. Each normal individual retains its various physiological and psychological needs and powers intact, not necessarily sacrificing any of them for the good of the community. In ants, however, the female individuals, of which the society properly consists, are not all alike but often very different, both in their structure (polymorphism) and in their activities (physiological division of labor). Each member is _visibly_ predestined to certain social activities to the exclusion of others, not as a man through the education of some endowment common to all the members of the society, but through the exigencies of structure, fixed at the time of hatching, i.e., the moment the individual enters on its life as an active member of the community.

c) Owing to this pre-established structure and the specialized functions which it implies, ants are able to live in a condition of anarchistic socialism, each individual instinctively fulfilling the demands of social life without "guide, overseer, or ruler," as Solomon correctly observed, but not without the imitation and suggestion involved in an appreciation of the activities of its fellows.