Chap, VIII.] CELL-MAKING INSTINCT. 353 



to our humble-bees could exist in large numbers in any 

 country; and let us "further suppose that the community 

 lived through the winter, and consequently required a 

 store of honey : there can in this case be no doubt that 

 it would be an advantage to our imaginary humble-bee 

 if a slight modification in her instincts led her to make 

 her waxen cells near together, so as to intersect a little ; 

 for a wall in common even to two adjoining cells would 

 save some little labour and wax. Hence it would con- 

 tinually be more and more advantageous to our humble- 

 bees, if they were to make their cells more and more 

 regular, nearer together, and 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 labour and wax would be 

 saved. Again, from the same cause, it would be advan- 

 tageous to the M elipona, 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 sur- 

 faces ; 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 labour and 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 inter- 



