LIFE-HISTORY OF BOMBUS 29 



injects through her mouth a little of the mixture 

 amongst the larvae, which devour it greedily. Her 

 abdomen contracts suddenly as she injects the food, 

 and as soon as she has given it she rapidly closes 

 up the hole with her mandibles. While the larvae 

 remain small they are fed collectively, but when they 

 grow large each one receives a separate injection. 



As the larvae grow the queen adds wax to their 

 covering, so that they remain hidden. When they 

 are about five days old the lump containing them, 

 which has hitherto been expanding slowly, begins 

 to enlarge rapidly, and swellings, indicating the 

 position of each larva, begin to appear in it. Two 

 days later, that is, on the eleventh day after the 

 eggs were laid, the larvae are full-grown, and each 

 one then spins around itself an oval cocoon, which 

 is thin and papery but very tough. The queen 

 now clears away most of the brown wax covering, 

 revealing the cocoons, which are pale yellow. 



These first cocoons number from seven to six- 

 teen, according to the species and the prolificness of 

 the queen. They are not piled one on another, but 

 stand upright side by side, and they adhere to one 

 another closely, so that they seem welded into a 

 compact mass. They do not, however, form a flat- 

 topped cluster, but the cocoons at the sides are 

 higher than those in the middle, so that a groove is 

 formed ; this groove is curved downwards at its 

 ends, and in it the queen sits, pressing her body 

 close to the cocoons, and stretching her abdomen 

 to almost double its usual length so that it will 



