MUTUAL AID AND COMMUNAL LIFE AMONG ANIMALS 389 



ing raises the temperature of the bees' bodies, and this warmth 

 given off to the air, also helps make evaporation more rapid. 

 In addition to bringing in food the workers also bring in, when 

 necessary, "propolis," or the resinous gum of certain trees, 

 which they use in repairing the hive, as closing up cracks and 

 crevices in it. 



In many of the cells there will be found, not pollen or 

 honey, but the eggs or the young bees in larval or pupal con- 

 dition (Fig. 243). The queen moves about through the hive, 

 laying eggs. She deposits only one egg in a cell. In three 

 days the egg hatches, 

 and the young bee ap- 

 pears as a helpless soft, 

 white, footless grub or 

 larva. It is cared for 

 by certain of the 

 workers, that may be 

 called nurses. These 

 nurses do not differ 

 structurally from the 

 other workers, but they 

 have the special duty 

 of caring for the help- 

 less young bees. They 

 do not -go out for pol- 

 len or honey, but stay in the hive. They are usually the 

 new bees i. e., the youngest or most recently added workers. 

 After they act as nurses for a week or so they take their 

 places with the food-gathering workers, and other new bees 

 act as nurses. The nurses feed the young or larval bees at 

 first with a highly nutritious food called bee jelly, which the 

 nurses make in their stomach, and regurgitate for the larvae. 

 After the larvae are two or three days old they are fed with pollen 

 and honey. Finally, a small mass of food is put into the cell, 

 and the cell is " capped " or covered with wax. Each larva, 

 after eating all its food, in two or three days more changes into 

 a pupa, which lies quiescent without eating for thirteen days, 

 when it changes into a full-grown bee. The new bee breaks 

 open the cap of the cell with its jaws, and comes out into the 

 hive, ready to take up its share of the work for the community. 

 In a few cases, however, the life history is different. The nurses 

 26 



c^. 243. Cells containing eggs, larvae, and pupse 

 o*he honeybee. The lower, large, irregular cells 

 are the queen cells. (After Benton.) 



