INSTINCT 381 



aggregated into a mass, like the cells of the Melipona; 

 for in this case a large part of the bounding surface of 

 each cell would serve to bound the adjoining cells, and 

 much labor and wax would be saved. Again, from the 

 same cause, it would be advantageous to the Melipona 

 if she were to make her cells closer together, and more 

 regular in every way than at present; for then, as we 

 have seen, the spherical surfaces would wholly disappear 

 and 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 economizing 

 labor and wax. 



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

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

 ral selection having taken advantage of numerous succes- 

 sive, slight modifications of simpler instincts; natural se- 

 lection 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 the con- 

 struction of cells of due strength and of the proper size 

 and shape for the larvae, this being effected with the 

 greatest possible economy of labor and wax; that indi- 

 vidual swarm which thus made the best cells with least 

 labor, and least waste of honey in the secretion of wax, 



