CH. VIIl] BEES AND THEIR CELLS 169 



"distribute themselves with maximum density, not only on each 

 "side separately, but on the two considered jointly. This, as a 

 "case of instinct, is certainly remarkable, but the possibilities 

 "of trial and error are sufficient to account for it. It is not 

 "unreasonable to expect that the bees should learn how to 

 "employ the largest possible number of themselves on a piece 

 "of wax to be excavated, this being a thing which they would 

 "naturally try to do; though it would be strange, in comparison, 

 "if they tried to effect those other two ends, of maximum 

 "economy in wax, and maximum strength of structure, which, 

 "as a matter of fact, they do effect." 



