BEE 455 out, is very unfavorable for the maintenance of a pure air ; the black hole of Calcutta is the only human receptacle which can be compared to it ; a taper is very soon extinguished in a globe of the dimensions and with the aperture of a beehive ; and yet these insects, as easily suffocated as any other, get along very well, and their respiration is accompanied by the usual absorption of oxygen and excretion of carbonic acid gas. With all this closeness of the air in the hive, direct examination has proved that it is nearly as pure as atmospheric air ; neither the contents of the hive nor the bees themselves have any power of evolving oxygen, but the air is renewed through the door of the hive, where an inward current is produced, whenever required, by the rapid agitation of the wings of the bees. Some of the workers are always thus employed in ven- tilating the hive, which they do by planting themselves near the entrance, and imitating the action of flying; in this way the impulse which would carry them forward in flight is exerted on the air, producing a powerful back- ward current ; this fact explains the humming sound heard in the interior of an active hive, especially in the warmest days. From their active respiration the temperature of a hive is very high, varying from 73 to 84 F., and on some occasions rising to 106 ; they are very sensitive to thermometrical changes, the warm sun exciting them to vigorous action, and cold reducing them to a torpid state. The instincts, and in the belief of many the intelligence of the bee, are remarkably displayed in the prep- aration of the hive, the construction of the cells, and in the phenomena of swarming. The first thing done on entering a new hive is to clean it thoroughly, to stop all crevices, and lay the foundation for the comb. Wax is not the only material used by bees in their archi- tecture ; besides this, they employ a reddish brown, odoriferous, glutinous resin, more te- nacious and extensible than wax, called pro- polis, which they obtain from the buds of the poplar and birch and from various resinous trees. This adheres so strongly to the legs of the bee, that its fellow laborers are obliged to remove it, which they do with their jaws, ap- plying it immediately to every crevice and pro- jection in the hive, to the interior of the cells, and to the covering of any foreign body too heavy for them to remove ; in this way even large snails are hermetically sealed and pre- vented from imparting a noxious quality to the air. Bees will carry home many artificially prepared glutinous substances in their tarsal baskets. After the workers have secreted a sufficient amount of wax, the construction of the combs commences. These are formed into parallel and vertical layers, each about an inch thick, the distances between the surfaces of each being about half an inch for the passage of the bees. They may extend the whole breadth and height of the hive, consisting of thin partitions enclosing six-sided cells, about half an inch deep and a quarter of an inch in diameter. The bottom of each cell has the shape of a flattened pyramid with three rhom- bic sides, like the diamonds on playing cards ; this gives the greatest strength and greatest capacity with the least expenditure of mate- rial. Maraldi had determined that the two angles of the rhomb should be 109 28' and 70 32' by mathematical calculation, and by actual measurement they are 110 and 70 . There is nothing in the shape of the antennae, mandibles, or legs of the bee which should determine these angles in the cells. From the fact that bees stand as close as they can, each depositing its wax around it, some have main- tained that the form and size of the insect determine the shape of the cell ; that the mathematical accuracy of the cell depends on its form and structure and not on its instinct ; and that the cell form is inevitable. The foun- dation is a solid plate of wax, of a semicircular form, in which a vertical groove is scooped out of the size of a cell, which is strengthened by further additions of wax ; on the opposite side two other grooves are formed, one on each' side of the plane opposite the first ; after the bottom is formed, the walls are raised round the sides. The cells of the first row, by which the comb is attached to the roof of the hive, have five sides instead of six, the roof forming one. The first cell determines the position of all that succeed it ; and two are not, in ordi- nary circumstances, begun in different parts of the hive at the same time. The laborers fol- low each other in quick succession, each one adding a little to the work ; when a few rows have been constructed in the central comb, two other foundation walls are begun, one on each side of it, at the distance of one third of an inch, and parallel to it, and then two others as the former are advanced ; the comb is thus enlarged and lengthened, the middle being al- ways the most prominent. If all their founda- tions were laid at the same time, it would be difficult for them to preserve their parallelism, which is perfect only at the last stage of the building process. Besides the vacancies be- tween the cells, which form the highways of the hive, the combs are pierced with holes, to permit easy communication, and prevent loss of time in going round. The symmetry of the architecture of bees is more observable in their work looked at as a whole than in its details, as they often build irregularly to adapt the structure to different localities and various un- favorable circumstances; different-sized cells are made for the larvre of workers, males, and queens; those for honey and pollen magazines are twice as large as ordinary cells, and so placed that their mouths are upward, for the easier retention of their contents. These sup- posed defects are generally the results of cal- culation, and, when mistakes, are very soon remedied. The cells at first are whitish, soft, and translucent ; but they soon become yellow and firmer, and quite dark in an old comb.
