656 APPENDIX B. 



constitutional difference between the eggs of worker-wasps and 

 the eggs of queens ; and that their eggs are not different we see, 

 first, in the fact that occasionally the worker-wasp is fertile and 

 lays drone-producing eggs, and we see secondly that (if in this 

 respect they are like the bees, of which, however, we have no 

 proof) the larva of a worker- wasp can be changed into the larva 

 of a queen-wasp by special feeding. But be this as it may, we 

 have good evidence that the feeding determines everything. tSays 

 Dr. Ormerod, in his British Social Wasps : — 



" When the swarm is strong and food plentiful . . . the well fed 

 larvae develop into females, full, large, and overflowing with fat. There are 

 all gradations of size, from the large fat female to the smallest worker. . . . 

 The larger the wasp, the larger and better developed, as the rule, are the 

 female organs, in all their details. In the largest wasps, which are to be the 

 queens of another year, the ovaries differ to all appearances in nothing but 

 their size from those of the larger worker wasps. . . . Small feeble swarms 

 produce few or no perfect females ; but in large strong swarms they are found 

 by the score." (pp. 248-9) 



To this evidence add the further evidence that queens and 

 workers pass through certain parallel stages in respect of their 

 maternal activities. At first the queen, besides laying eggs, builds 

 cells and feeds larvae, but after a time ceases to build cells, and 

 feeds larvaj only, and eventually doing neither one nor the other, 

 only lays eggs, and is supplied with food by the workers. So it 

 is in part with the workers. While the members of each succes- 

 sive brood, when in full vigour, build cells and feed larvae, by- 

 and-by they cease to build cells, and only feed larvae : the ma- 

 ternal activities and instincts undergo analogous changes. In 

 this case, then, we are not obliged to assume that only by a pro- 

 cess of natural selection can the differences of structure and in- 

 stinct between queens and workers be produced. The only way 

 in which natural selection here comes into play is in the better 

 survival of the families of those queens which made as many 

 cells, and laid as many eggs, as resulted in the best number of 

 half-fed larvae, producing workers ; since by a rapid multiplica- 

 tion of workers the family is advantaged, and the ultimate pro- 

 duction of more queens surviving into the next year insured. 



The differentiation of classes does not go far among the wasps, 

 because the cycle of processes is limited to a year, or rather to 

 the few months of the summer. It goes further among the hive- 

 bees, which, by storing food, survive from one year into the next. 

 Unlike the queen-wasp, the queen-bee neither builds cells nor 

 gathers food, but is fed by the workers : ^gg laying has become 

 her sole business. On the other hand the workers, occupied ex- 

 clusively in building and nursing, have the reproductive organs 

 more dwarfed than they are in wasps. Still we see that the 

 worker-bee occasionally lays drone-producing eggs, and that, by 



