The cells in which queens are bred bear in size and shape some resemblance to a ground or pea nut. They are often irregular in form, being sometimes curved, or short and thick, according to the space below their point of attachment, which is most frequently the lower edge or the side edge of a comb, or sometimes a mere projection or angularity in the general surface of a comb. Queen cells open downward instead of being built horizontally like drone and worker cells (figs. 62 and 63). [Illustration: Fig. 10.--Comb building--side of hive removed. (Original.)] Into the material used in constructing brood combs bees often incorporate bits of wax and fiber-like gnawings of cocoons from old combs in which brood has been reared, and if given cappings or trimmings of combs they will work them all over and utilize most of the material. Also when the bees have abundant supplies of pollen much of this is incorporated into the material of brood combs, thus saving the costlier substance--wax. Such combs show at once by their brownish or straw color, even when first constructed, that they are not made of wax alone. It will readily be seen from the above that the quantity of honey consumed by the bees in producing a pound of comb must vary greatly, for if the comb is designed for surplus honey it will be made of newly secreted wax, while if for brood other material will, as just stated, replace a portion of the wax. The amount of honey coming in varies from day to day, and it is difficult to estimate how much is consumed in feeding and keeping warm the brood: moreover, a high temperature is required in the hive to facilitate the secretion and working of wax, necessitating, of course, extra food consumption when the outside temperature is low. Accordingly estimates as to the amount of honey required to produce 1 pound of comb range from 5 pounds to 25 pounds. More accurate experiments are needed in this direction before anything positive can be stated. Until then 18 to 20 pounds might be looked upon as nearest the correct figure for white surplus combs, and half as much for dull straw-colored or brownish combs built for brood rearing. DEVELOPMENT OF BROOD.