Page:Popular Science Monthly Volume 73.djvu/463

This page has been proofread, but needs to be validated.
459
ZOOLOGY

the confines of my subject. But if the student of lower forms should find well-defined principles of biological association and principles of animal conduct, it is not only his privilege, it is in a sense his duty as well to bring these to the consideration of the students of human social and ethical relations. Unless in these matters there has been a break in the continuity of evolution, the simpler relations to be observed in lower animals must surely possess a profound interest—and perhaps more.

In a true sense, any of the many-celled animals is a community, whose constituent members are the differentiated tissue-cells, which have undertaken the various tasks of digestion, contraction, sensation and the rest. By far the majority of animals are cell-communities of this nature. Considering these as individuals, though of a secondary order, we find some communities made up of several animals which have banded together for mutual support and defense, giving us as in the wolf-pack a counterpart of the lowest associations of savage men. But among insects especially we find colonies of numerous multicellular individuals which may be so rigidly specialized for the performance of certain tasks that we can not avoid the use of terms applied to civilized human groups in describing their differentiation and division of labor. Some colonies of bees comprise queens and drones and only one kind of sterile workers, though when newly hatched these last serve as guards and nurses, taking the field as foragers for pollen and honey only later in life. In various ant-colonies we shall find workers who serve as herdsmen, devoting their time to the care of the ant-cattle or aphids; again there are masons, and gardeners, and carpenters, and soldiers of various ranks, while in the honey-ant some individuals may serve as living receptacles for the tribal stores of food. Each kind undertakes one of the tasks that are vital for the life of the community as a whole. Instinctive and unreasoned their activities may be, and undoubtedly are, but the economic and social relations of the component members of the colony are strikingly analogous to certain fundamental phenomena of human societies. But still more wonderful are the cases that may be found among hornets and wasps. A fertile female overwinters and places her first-laid eggs in the chambers of a simple nest that she constructs herself. When the young of the first brood hatch, she provides them with food, enlarges the nest, and continues the task of egg-laying, while her first offspring relieve her of her former duties as they become able. They enlarge the nest, they care for their younger kin as they hatch, they forage abroad for the food-supplies for the colony. And so the community that begins life in the early spring with a solitary animal advances during the passing weeks to a degree of complexity that is truly astounding. As an epitome of insect social evolution it gives in a few weeks a review of the process that in other