Two hundred years ago, the author of "Robinson Crusoe" paid his respects to those who tried to mobilize the race prejudice of "true born Englishmen" against the followers of William of Orange, in words that some of our "hundred per cent. Americans' might ponder with profit:

These are the heroes that despise the Dutch,
And rail at new-come foreigners so much;
Forgetting that themselves are all derived
From the most scoundrel race that ever lived;
A horried crowd of rambling thieves and drones
Who ransacked kingdoms and dispeopled towns;
The Pict, and Painted Briton, treach 'rous Scot;
By hunger, theft, and rapine, hither brought;
Norwegian pirates, Buccaneering Danes,

Whose red-haired offspring everywhere remains,

Who join'd with Norman French, compound the breed,
From whence your true-born Englishmen proceed.

There are those who fear for civilization. Of what are they afraid? Civilization is not necessarily threatened, whether by imperialists or communists; our civilization may be the aggregate of our material and intellectual possessions. Creative intelligence, however, is indifferent to the language which transmits the intellectual fruits of man's genius-whether it be Anglo-Saxon or Prussian, Latin or Slav, indifferent even to the color of the hand that bears aloft the torch of enlightenment and progress, let it be yellow, white or black. So far as intelligence and progress are concerned, the future is a sporting proposition, and the sportsman's attitude is to let the best man win.

The general aim of civilization is dominion over nature-the more efficient control of natural forces. There are doubtless some who still think that man's subjection to nature is a law of God, and that a social order once established must not be changed. Progress, however, is inevitable, though privilege and authority, timidity and prejudice will always oppose the creative advance of intelligence. To defy the spirit of progress in the name of either religion or law is superstition; the true prophet is a poet who sees in creative evolution the display of divine intelligence.

What the world needs to-day is more of the optimism of the progressive and a little less of the pathological fear of the standpatter, more faith in creative evolution, more hope of reaching yet higher levels of achievement and more of that freedom from prejudice called charity, another name for love, the productive passion.

IN

SOCIAL LIFE AMONG THE INSECTS1

By Professor WILLIAM MORTON WHEELER

BUSSEY INSTITUTION, HARVARD UNIVERSITY

LECTURE II. WASPS SOLITARY AND SOCIAL

N the preceding lecture I gave a brief account of the rudimentary social life of certain beetles and called attention to the fact that in all or nearly all of them the male cooperates with the female parent in victualing or protecting the offspring. I endeavored to show that all these societies have their inception or raison d'être in the specialized feeding habits of the parents and that in all of them the food is of vegetable origin, abundant but not very nutritious in some of the cases (dung and rotten wood in the Scarabæidæ, Passalidæ and Phrenapates), in others highly nutritious, but obtainable only in small quantities at a time (living plant-tissues and honey-dew in the case of the Tachigalia beetles, ambrosia of the Ipida and Platypodidae). The adequate exploitation of such food-supplies is necessarily time-consuming and has evidently led to a lengthening of the adult lives of the beetles. This in turn has naturally brought about an overlapping of the juvenile by the parent generation, thus enabling the parents to acquire contact and acquaintance with their young and an interest in providing them with the same kind of food as that on which they themselves habitually feed. In the insects which I shall consider in this lecture, we find a series of societies originating in a very different type of feeding and leading to much more complicated and more definitely integrated associations.

Although the wasps have attracted fewer investigators than the ants and bees, they are of even greater interest to the student who is tracing the evolution of specialized instincts and social habits. The wasp group is one of enormous size and is really made up of two great complexes, the Sphecoids and the Vespoids, together comprising more than a dozen families and some 10,000 species. Of these only about 800 are clearly social. We have more or less fragmentary behavioristic studies of scarcely 5 per cent. of ,all the species. Yet they cover a sufficient number of forms to enable us to establish the following generalizations:

(1). The structure and behavior of the Sphecoids and Vespoids

1 Lowell Lectures.

show that they must have arisen from what have been called Parasitic Hymenoptera, and the structure of the ants and bees shows that they in turn must have arisen from primitive Sphecoids or Vespoids.

(2). The social wasps comprise several groups which have evolved independently from primitive, solitary Vespoids, but there are also a few Sphecoids that exhibit subsocial propensities.

(3). Both the Sphecoids and the Vespoids are primarily predaceous and feed on freshly captured insects, but the adults are fond of visiting flowers and feeding on nectar. Some social wasps store honey in their nests, but it is probably not an exclusive or essential constituent of the larval food. One small and aberrant group of solitary Vespoids, the Masarinæ, however, provision their cells with a paste of honey and pollen, like the solitary bees. The insect prey on which at least the young of nearly all the wasps subsist, being extremely rich in fats and proteids, is an ideal food, but has to be provided in larger quantity than such concentrated vegetable substances as pollen and nectar. It is also scarcer and more difficult to obtain. Hence the definite tendency in adult wasps towards a honey regimen at least for the purpose of eking out the primitive animal diet.

(4). We are able to observe in the social wasps more clearly than in other social insects the peculiar phenomenon which I have called "trophallaxis," i. e., the mutual exchange of food between adults and their larval young.

(5). The study of the wasps and of their ancestors among the Parasitic Hymenoptera furnishes us with a key to the understanding of parthenogenesis and the peculiar dominance of the female sex (gynarchy) which is retained throughout the whole group of stinging Hymenoptera (wasps, bees and ants).

(6). In the social wasps we witness the first gradual development of a worker caste and also of polygyny and swarming.

(7). We observe in wasps a high degree of modifiability of behavior and an extraordinary development of memory, endowments which have led McDougall to claim for them "a degree of intelligence which (with the doubtful exception of the higher mammals) approaches most nearly to the human," and Bergson to point to their activities as one of the most telling arguments in favor of his intuitional theory of instinct. Although I believe that these and many other authors have been guilty of some exaggeration the wasp's psychic powers compared with those of most. other insects or even of many of the lower Vertebrates seem to me, nevertheless, to be sufficiently remarkable.

We shall have to examine each of these generalizations more closely. Some of them may be considered forthwith, others more

advantageously after the description and illustration of a selected series of species.

Recent studies of the parasitic, or as I prefer to call them with O. M. Reuter, the "parasitoid" Hymenoptera, have revealed certain peculiar traits which recur in a modified form in the behavior of their Sphecoid and Vespoid descendants. But what are these parasitoids? You are all familiar with the fact that a large number of insects regularly lay their eggs on or in plants and that the hatching larvæ devour the plant tissues and eventually pupate and emerge as insects which repeat the same cycle of behavior. There is, however, another immense, but less conspicuous, assemblage of insects that lay their eggs on or in the living eggs, larvæ, pupa and adults of other insects, and the eggs thus deposited develop into larvæ which gradually devour the softer tissues in which they happen to find themselves. Species that behave in this manner are not true parasites, but extremely economical predators, because they eventually kill their victims, but before doing so spare them as much as possible in order that they may continue to feed and grow and thus yield fresh nutriment just as it is needed. For this reason and also because, as a rule, only the larval insect behaves in the manner described, it is best called a "parasitoid." The adult into which it develops is, in fact, a very highly organized, active, free-living creature, totally devoid of any of the stigmata of "degeneration" so common among parasites, and with such exquisitely perfected sensory, nervous and muscular organs that it can detect its prey in the most intricate environment and under the subtlest disguises.

The parasitoids exhibit another peculiarity which was destined to acquire great importance in their descendants, the wasps, bees and ants, namely, parthenogenesis, or the ability of the female to lay unfertilized eggs capable of complete development. As a rule, if not always, these parthenogenetic eggs develop into males, whereas fertilized eggs laid by the same female develop into individuals of her own sex. Thus the female has become to some extent independent of the male in the matter of reproduction. It will be seen that if the parthenogenetic egg were able to develop into a female, as it frequently does in certain insects like the plant-lice, the male might become entirely superfluous. There are a few insects in which this has occurred or in which the male appears only at infrequent intervals in a long series of generations. But matters have not come to such a pass in the parasitoids or in the wasps, bees and ants, though these insects have perfected another method of reducing the male to a mere episode in the life of the female. Individuals of this sex are provided with a small muscular sac, the

spermatheca, which is filled with sperm during the single act of mating, and this sac is provided with glands, the secretion of which may keep the sperm alive for months or even years. According to a generally accepted theory, the female can voluntarily contract the wall of her spermatheca and thus permit sperm to leave it and fertilize the eggs as they are passing its orifice on their way to being laid, or she can keep the orifice closed and thus lay unfertilized eggs. The mother can thus control the sex of her offspring or if she has failed to mate, or has exhausted all the sperm in her spermatheca, may nevertheless be able to lay male-producing eggs. There seems also to be something compensatory, or regulatory, in this ability of the female parasitoid to produce males parthenogenetically, for if she be unable to meet with a male-and this predicament is very apt to arise among such small and widely dispersed animals as insects-she can produce the missing sex and thus increase the chances of mating for the next generation of females.

Certain facts indicate that the sex of the egg may not be determined in the manner here described, but their consideration must be postponed till they can be taken up in connection with the honey-bee. We are justified, notwithstanding, in regarding the female parasitoid, wasp, bee or ant, after she has appropriated and stored in her spermatheca all the essential elements of the male, as a potential hermaphrodite. The body, or soma, of the male, after mating, thus really becomes superfluous and soon perishes. In the solitary wasps the male is a nonentity, although in a few species he may hang around and try to guard the nest. But in the bees, ants and social wasps he has not even the status of a loafing policeman, and all the activities of the community are carried on by the females, and mostly by widows, debutantes and spinsters. The facts certainly compel even those who, like myself, are neither feminists nor vegetarians, to confess that the whole trend of evolution in the most interesting of social insects is towards an ever increasing matriarchy, or gynarchy and vegetarianism.

Now if we carefully observe a parasitoid while she is ovipositing in her prey, we obtain a clue to the meaning of the peculiar behavior of the solitary wasps which has led Fabre to certain erroneous conclusions and philosophers like Bergson to his peculiar interpretation of instinct. The parasitoid is furnished at the posterior end of her body with a well-developed ovipositor, a slender, pointed instrument for piercing the tough integument of her victim. But this instrument also has another function, namely, that of making punctures through which droplets of the victim's blood may exude and be devoured by the parasitoid. She may often be