INTERRELATIONS OF INSECTS 



283 



ipear underneath the abdomen (Fig. 104) ; these are transferred to the 

 outh, as described on page 229, and are masticated with a fluid, 



:reted by cephalic glands, which alters the chemical composition of 

 the wax and makes it plastic. 



The workers now contribute their wax to form a vertical, hanging 

 septum, on the opposite sides of which they proceed to bite out pits 

 the bottoms of the future cells using the 

 excavated wax in making the cell walls. The 

 bottom of each cell consists of three rhombic 

 plates (Fig. 285, A), and the cells of one side 

 interdigitate with those of the other side (Fig. 

 285, B) in such a way that each rhomb serves 

 for two cells at once. Wax is such a precious 

 substance that it is used (instinctively, how- 

 ever) always with the greatest economy; the 

 cell walls, are scraped to a thinness of 3^80 r 

 Moo of an inch, and nowhere is more wax used 

 than is sufficient for strength; one pound of wax 

 makes from 35,000 to 50,000 worker cells. The 

 cells, at first circular in cross section, become 

 hexagonal from the mutual interference of 

 workers on opposite sides of the same wall; 

 the form is, however, by no means a regular 

 hexagon in the mathematical sense, for it is difficult to find a cell with 

 errors of less than 3 or 4 degrees in its angles. (Cheshire.) Worker 

 cells are one fifth of an inch in diameter, while the larger cells, destined 

 for drones or to hold honey, are one quarter of an inch across. 



To strengthen the edges of cells or to fill crevices, the workers use 

 propolis, the sticky exudation from the buds or leaf axils of poplar, fir, 

 horse-chestnut or other trees ; though they will utilize instead such arti- 

 ficial substances as grease, pitch or varnish. As winter approaches, the 

 bees apply the propolis liberally, making their abode tight and 

 comfortable. 



Larval Development. When the brood cells are ready, the queen, 

 attended by workers, lays an egg in each cell and has no further con- 

 cern as to its fate. After three days the egg discloses a footless grub 

 (Figs. 286, 287) which depends at first upon the milky food that bathes 

 it and has been supplied from the mouths of the worker nurses. Later 

 the larva is weaned by its nurses to pollen, honey and water. As the 

 stomach and the intestine of the larva do not communicate with each 



PIG. 285. A, bases of 

 comb cells; B, section of 

 comb. Somewhat e n- 

 larged. After CHESHIRE. 



