126 



HYMENOPTERA. 



of two cells, the base being donl)le Avhilc the mouth is 

 single. Tlmt on the line a, h, has three sides at one end, 

 uiiitcd b}' two long sides Avith one at the other, and thus two 

 of the opposite sides are not parallel ; at c, cZ, two sides at 



b 



c d e / 



Fig. 78. 



either end are united by two long sides, these last being par- 

 allel ; and at e, /, the mouth of the compound cell has seven 

 sides. Each has a partition at its base, separating the two 

 originally distinct cells, and each was lined with a cocoon, 

 showing that it had been used for rearing young. At gr, not 

 only has the partition between the combining ceUs disappeared, 

 but also three of the sides of each cell." 



The bees do not appear to have any systematic way of mak- 

 ing a transition from worker to drone cells, which are one-tifth 

 larger than the former. More commonly, they effect it by a 

 gradual alteration of the diameters, thus enlarging a worker 

 into a drone, or narrowing a drone into a worker cell. This 

 alteration is usually made in from four to six rows. In one case 



