S6 THE Entomologist's record. 



" never in any case depends on mere influences of nutrition, such as 

 affect the development of each individual," I think it only wants 

 sufficiently wide experiment for him to modify his opinion, and then 

 what becomes of the assumption based on these premises ? And it is on 

 these assumptions that the Professor builds up his theory that in the 

 germ-plasm of an egg of every social insect there are three distinct 

 reproductive systems, two of which fail and one of which develops, 

 and determines the character of the insect which shall ultimately be 

 produced under certain stimuli — the "three sorts of primary con- 

 stituents in the germ " being the male, and two forms of the female. 



Having thus come to the conclusion that want of nutrition cannot 

 produce the disappearance of a typical organ, the Professor suggests 

 that the facts he has brought forward " support neither the idea that 

 the degeneration of the ovary of the workers is a direct consequence of 

 poverty of nutrition, nor the view that an increased sensitiveness of 

 the ovary to the influence of nourishment is here concerned. But 

 they do show that j^oor nourishment acts as the stimnJus for the latent 

 primary constituents for the tcorJcers in the germ-plasm; — not only for 

 those of the ovary, hut also for those of all characters by tchich the 

 worker is distinguished from the queen." 



Now if this means anything, it means this — that the poor feeding 

 of a certain brood of larvje of flies or butterflies gives rise to small 

 specimens with ill-developed external structural parts, but so far as 

 the Professor can guess (for he does not tell us that he tested the 

 matter) there were no structures (internal or external) absent, they 

 were only smaller, and the reason for supposing that the internal 

 structures were wholly present was not based on an examination of the 

 structures, but was a mere matter of supposition based on examining 

 the external organs ; and that not having pursued the experiment 

 which resulted in producing a first brood of small and ill-developed 

 flies to a second generation, but only to the extent of seeing that the 

 first brood paired and laid fertile eggs, the Professor is able to assert 

 that there was no increased sensitiveness of the ovary to the influence 

 of nourishment, and therefore on these powerful premises the above 

 italicised law is laid down. 



The Professor has here reached the point in his argument where he 

 has satisfied himself that poor food has not been the stimulus which 

 directly, even in the course of unknown generations, produced the im- 

 perfect development of the ovaries of the workers, and hence 

 we may assume conversely, produced the highly developed con- 

 dition of the ovaries of the queen, that the high feeding to 

 which we know the queen is subjected, in fact, has nothing to do 

 with the enhanced development of the latter ; that there are in every 

 egg two indefinite somethings called " ids " — a male-id, and a female- 

 id — and that fertilisation, or its absence, determines which of these 

 " ids" shall develop, and that in the former case (fertilisation) the 

 female-id is developed, in the latter case (absence of fertilisation) the 

 male-id is developed. Fertilisation, then, having determined which 

 " id" shall be developed, if it be a female-id that is developing, then 

 the female-id is in its turn composed of two parts — a worker-id part 

 and a queen-id part — and the kind of food supplies the stimiilus which 

 determines whether the fenuile-id shall produce a worker or a queen. 

 " blow processes of selection have gradually changed the * female-ids ' 



