INSTINCT 211 



have seen, the spherical surfaces would wholly dis- 

 appear, and would all be replaced by plane surfaces ; 

 and the Melipona would make a comb as perfect as that 

 of the hive-bee. Beyond this stage of perfection in 

 architecture, natural selection could not lead ; for the 

 comb of the hive-bee, as far as we can see, is absolutely 

 perfect in economising wax. 



Thus, as I believe, the most wonderful of all known 

 instincts, that of the hive -bee, can be explained by 

 natural selection having taken advantage of numerous, 

 successive, slight modifications of simpler instincts ; 

 natural selection having by slow degrees, more and 

 more perfectly, led the bees to sweep equal spheres 

 at a given distance from each other in a double 

 layer, and to build up and excavate the wax along 

 the planes of intersection. The bees, of course, no 

 more knowing that they swept their spheres at one 

 particular distance from each other, than they know 

 what are the several angles of the hexagonal prisms 

 and of the basal rhombic plates. The motive power of 

 the process of natural selection having been economy 

 of wax ; that individual swarm which wasted least 

 honey in the secretion of wax, having succeeded best, 

 and having transmitted by inheritance its newly ac- 

 quired economical instinct to new swarms, which in 

 their turn will have had the best chance of succeeding 

 in the struggle for existence. 



No doubt many instincts of very difficult explanation 

 could be opposed to the theory of natural selection, — 

 cases, in which we cannot see how an instinct could 

 possibly have originated ; cases, in which no interme- 

 diate gradations are known to exist ; cases of instinct 

 of apparently such trifling importance, that they could 

 hardly have been acted on by natural selection ; cases 

 of instincts almost identically the same in animals so 

 remote in the scale of nature, that we cannot account 

 for their similarity by inheritance from a common 

 parent, and must therefore believe that they have 

 been acquired by independent acts of natural selection. 



