126 



HYMENOPTERA. 



of two cells, the base being double while the mouth is 

 single. That on the line a, b, has three sides at one end, 

 united by two long sides with one at the other, and thus two 

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



a b 



'9 



c d c / 



Fig. 78. 



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

 allel ; and at <?, /, the mouth of the compound cell has scA-en 

 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 j/, not 

 only has the ])artition between the combining cells 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 woi'ker to drone cells, which are one-fifth 

 larger than. the former. jNIore connnonl}-, the}- 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 usuall}' made in from four to six rows. In one case 



