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 larvae 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