_The Egg._—Although the egg of the parent is the source of the origin of the bee, we cannot abruptly commence from this point, for the preliminary labours of the mother are indispensable to the evolution of its offspring. This egg has to be placed in a suitable depository, together with the requisite food for the sustenance of the vermicule that will be disclosed from it. Instinct instructs the parent where and how to form the nidus for its egg. These depositories differ considerably in the several genera, but, as a general rule, they are tubes burrowed by the mother either in earth, sand, decaying or soft wood, branches of plants having a pith, the halm of grain, cavities already existing in many substances, and even within the shells of dead snails. These perforations are sometimes simple, and sometimes they have divergent and ramifying channels. Sometimes they are carefully lined with a silky membrane secreted by the insect, and sometimes they are hung with a tapestry of pieces of leaves, cut methodically from plants, but some leave their walls entirely bare. All these particulars I shall have ample opportunity to note in the special descriptions of the genera. I merely indicate them to show how various are the receptacles for the offspring of our bees. [Illustration: Fig. 1. The Egg.] Before the egg is placed within its nidus, this is supplied with the requisite quantity of food needful for the support of the young to the full period of its maturity. The receptacle is then closed, and the same process is repeated again and again until the parent has laid her whole store of eggs. In other cases one tube, or its ramification, contains but one egg. These eggs are usually oblong, slightly curved, and tapering at one extremity; they vary in size according to the species, but are never, however, above a line in length, and sometimes they are very minute. When the stock of the mother bee is exhausted she leaves them to the careful nursing of nature, and the young is speedily evolved. She then wanders forth; time has brought senility; her occupation has gone; and she passes away; but her progeny survive to perpetuate the continual chain of existence.