368 OBJBOTIONB TO TEE TUEORT 



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 re- 

 placed 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 in- 

 stincts, 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 par- 

 ticular 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 construction of cells of due 

 strength and of the proper size and shape for the larvee, 

 this being effected with the greatest possible economy of 

 labor and wax; that individual swarm which thus made 

 the best cells with least labor, and least waste of honey in 

 the secretion of wax, having succeeded best, and having 

 transmitted their newly-acquired economical instincts to 

 new swarms, which in their turn will have had the best 

 chance of succeeding in the struggle for existence. 



OBJECTIONS TO THE THEORY OF liTATURAL SBLECTIOX AS 

 APPLIED TO INSTINCTS: NEUTER AND STERILE INSECTS. 



It has been objected to the foregoing view of the origin 

 of instincts that "the variations of structure and of instinct 

 must have been simultaneous and accurately adjusted to each 

 other, as a modification in the one without an immediate 

 corresponding change in the other would have been fatal."' 



