pacivakd] the social life of insects. 



347 



Fig. 258. 



they do not attack the larva? of their hosts, but steal their 

 bee-bread. 



The bumble or humble bee is truly social, and yet in a 

 manner quite its own. Besides the males and queens, there 

 are a large number of workers, but they do not assist in 

 building any cells, as the larvae in part make their own cells. 

 The habits of the humble bees in this country have been 

 studied with much attention by Mr. Putnam. He shows b}' 

 independent observation that the queen which has hiber- 

 nated, after selecting a site for her nest in an abandoned 

 mouse's-nest or stump, collects a small mass of pollen mixed 

 with honey, and in this deposits 

 from seven to fourteen eggs, grad- 

 ually adding to the pollen mass 

 until the first brood is hatched. 

 Now it seems that as soon as the 

 grubs begin to eat they make cavi- 

 ties in the mass, and when fully 

 grown spin an oval cocoon about 

 them. Thus the act of building 

 these oval cells is a purely mechan- 

 ical one. These grubs are in truth 

 unconscious automata. They, how- 

 ever, are in a degree aided by the 

 queen, who strengthens the thin walls of the cell by covering 

 them witii a thin layer of wax. The cells form an irregular 

 mass, but however thickly crowded together always retain 

 tiieir oval form (Fig. 259, 2, showing eggs laid in a pollen 

 mass on one end of a cell). It is this fact which leads us to 

 believe that the wasp or honey bee in building its six-sided 

 cells, did so in the begiitning from design, however instinc- 

 tive the act now is, and that the}^ are not compelled to do 

 so unconsciously and in obedience to certain laws of me- 

 chanics which they are forced to follow. 



The mechanical theory of the formation of the bee's cell 



27 



Leaf Cutter IJee at work. 



