divides this space into a few cells by means of transverse partitions (Fig. 236). In each cell she lays an egg, and puts with it enough food -flower pollen-to last the grub or larva through its life. She then waits in an upper cell of the nest until the young bees issue from their cells, when she leads them off, and each begins active life on its own account. The mining bees Andrena, which make little burrows (Fig. 237) in a clay bank, live in large colonies that is, they make their nest burrows close together in the same clay bank, but each female makes her own burrow, lays her own eggs in it, furnishes it with food-a kind of paste of nectar and pollen-and takes no further care of her young. Nor has she at any time any special interest in her neighbors. But with the smaller mining bees, belonging to the genus Halictus, several females unite in making a common burrow, after which each female makes side passages of her own, extending from the main or public entrance burrow. As a wellknown entomologist has said, Andrena builds villages composed of individual homes, while Halictus makes cities. composed of apartment houses. The bumblebee (Fig. 238), however, establishes a real community with a truly communal life, although a very simple one. The few bumblebees which we see in winter time are queens; all other bumblebees die in the autumn. In the spring a queen selects some deserted nest of a field mouse, or a hole in the ground, gathers pollen which she molds into

FIG. 236. Nest of carpenter bee, Ceratina dupla.

a rather large irregular mass and puts into the hole, and lays a few eggs on the pollen mass. The young grubs or larvæ which soon hatch feed on the pollen, grow, pupate, and issue as workers-winged bees a little smaller than the queen. These workers bring more pollen, enlarge the nest, and make irregular cells in the pollen mass, in each of which the queen lays an egg. She gathers no more pollen, does no more work except that of egg-laying. From these new eggs are produced more workers, and so on until the community may come to be pretty large. Later in the summer males and females are produced and mate. With the approach of winter all the workers and males die, leaving only the fertilized females, the queens, to live through the winter and found new communities in the spring.

The social wasps-as with the bees,

a

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FIG. 239-The yellow jacket, Vespa, a social
wasp:
a. Worker; b, queen.

there are many more kinds of solitary wasps than social ones-show a communal life like that of the bumblebees. The only yellow jackets and hornets that live through the winter are fertilized females or queens. When spring comes each queen builds a small nest suspended from a tree branch, or in a hole in the ground, which consists of a small comb inclosed in a covering or envelope open at the lower end. The nest is composed of "wasp paper," made by chewing bits of

weather-beaten wood taken from old fences or outbuildings. In each of the cells the queen lays an egg. She deposits in the cell a small mass of food, consisting of some chewed insects or spiders. From these eggs hatch grubs which eat the food prepared for them, grow, pupate, and issue as worker wasps,

FIG. 240.-At the left, nest of Vespa, a social wasp; at the right, nest of Vespa opened to show combs within. (From photographs.)

winged and slightly smaller than the queen (Fig. 239). The workers enlarge the nest, adding more combs and making many cells, in each of which the queen lays an egg. The workers provision the cell with chewed insects, and other broods of workers are rapidly hatched. The community grows in numbers and the nest grows in size until it comes to be the great ball-like oval mass which we know so well as a hornets' nest (Fig. 240), a thing to be left untouched. When disturbed, the wasps swarm out of the nest and fiercely attack any invading foe in sight. After a number of broods of workers has been produced, broods of males and females appear and mating takes place. In the late fall the males and all of the many workers die, leaving only the new queens to live through the winter.

Honeybees live together, as we know, in large communities.

We are accustomed to think of honeybees as the inhabitants of beehives, but there were bees before there were hives. The "bee tree" is familiar to many of us. The bees, in Nature, make their home in the hollow of some dead or decaying treetrunk, and carry on there all the industries which characterize the busy communities in the hives. A honeybee community comprises three kinds of individuals (Fig. 241)—namely, a fertile female or queen, numerous males or drones, and many infertile females or workers. These three kinds of individuals differ in external appearance sufficiently to be readily recognizable. The workers are smaller than the queens and drones, and the last two differ in the shape of the abdomen, or hind body, the abdomen of the queen being longer and more slender than that of the male or drone. In a single community there is one queen, a few hundred drones, and ten to thirty thousand workers. The number of drones and workers varies at different times of the year, being smallest in winter. Each kind of individual has certain work or business to do for the whole community. The queen lays all the eggs from which new bees are born; that is, she is the mother of the entire community. The drones or males have simply to act as royal consorts; upon them depends the fertilization of the eggs. The workers undertake all the food-getting, the care of the young bees, the

comb-building, the honey-making-all the industries with which we are more or less familiar that are carried on in the hive. And all the work done by the workers is strictly work for the whole community; in no case does the worker bee work for itself alone; it works for itself only in so far as it is a member of the community.

How varied and elaborately perfected these industries are may be perceived from a brief account of the life history of a

bee community. The interior of the hollow in the bee tree or of the hive is filled with "comb"-that is, with wax molded into hexagonal cells and supports for these cells. The molding of these thousands of symmetrical cells is accomplished by the workers by means of their specially modified trowellike mandibles or jaws. The wax itself, of which the cells are made, comes from the bodies of the workers in the form of small liquid drops which exude from the skin on the under side of the abdomen or hinder body rings. These droplets run together, harden and become flattened, and are removed from the wax plates, as the peculiarly modified parts of the skin which produce the wax are called, by means of the hind legs, which are furnished with scissorlike contrivances for cutting off the wax (Fig. 242). In certain of the cells are stored the pollen and honey, which serve as food for the community. The pollen is gathered by the workers from certain favorite flowers and is carried by them from the flowers to the hive in the "pollen baskets," the slightly concave outer surfaces of one of the segments of the broadened and flattened hind legs. This concave surface is lined on each margin with a row of incurved stiff hairs, which hold the pollen mass securely in place large joint with the (Fig. 242). The "honey" is the nectar of flowers which has been sucked up by the workers by means of their elaborate lapping the cutting surfaces and sucking mouth parts and swallowed into a sort of honey sac or stomach, then brought to the hive and regurgitated into the cells. This nectar is at first too watery to be good honey, so the bees have to evaporate some of this water. Many of the workers gather above the cells containing nectar, and buzz-that is, vibrate their wings violently. This creates currents of air which pass over the exposed nectar and increase the evaporation of the water. The violent buzz

FIG. 242.- Posterior leg of worker honey

bee. Concave surface of the upper

of the angle between the two large

segments of the leg.