66 



THE HONEY-BEE. 



under the weight of the constantly passing insects, 

 the margin at the opening of each cell is made four 

 or five times thicker than the walls. Then, as the 

 cells are lengthened, this thickness is reduced, always 

 remaining the same, however, at the actual margins. 

 Dr. Barclay also discovered that, though the tenuity of 

 the divisions is so great, each, in point of fact, consists 



FIG. 17. DIAGRAM SHOWING SLOPE OF CELLS. 



of two distinct layers agglutinated together. This 

 gives, again, an increase of strength, as any practical 

 builder would know who, in his " bressummers," 

 adopts the same method of attaining lightness and 

 power of sustaining great weights. 



The actual size of the cells in a hive varies con- 

 siderably, as we might expect. Without regarding 

 those for queen-progeny, we should anticipate that 



