THE DETERMINATION OF SEX. 



43 



determine the future destiny of their charge by changing the 

 diet, and this in some cases is certainly done. If a larva on 

 the way to become a worker receive by chance some crumbs 

 from the royal superfluity, the reproductive function may develop, 

 and what are called "fertile workers," to a certain degree above 

 the average abortiveness, result; or, by direct intention, a worker 

 grub may be reared into a queen bee. 



The following table, after a recent analysis by A. von Planta, shows the 

 differences of diet as far as solids are concerned. For queens 69.38 per 

 cent., for drones 72.75 per cent., and for workers 71.63 per cent, is water. 



From the above, it is seen that the queen larvce get a (juantity of fatty 

 material double that given to the workers. The drones at first receive a 

 large percentage of nitrogenous material, but this soon falls below the 

 share which workers and queens obtain. The fatty material, at first 

 large, soon falls to about a third of that given to the queens. Hence the 

 percentage of glucose, except at first, is so much larger than in the other 

 two cases. 



It is not necessary, however, to go into details to see the 

 importance of the main point, that differences of nutrition, in 

 great part at least, determine the all-important distinctions 

 between the development and retardation of femaleness. Nor 

 are there many facts more significant than this simple and well- 

 known one, that within the first eight days of larval life, the 

 addition of a little food will determine the striking structural 

 and functional differences between worker and queen. 



Eimer has drawn attention to the interesting correlation ex- 

 hibited in the fact that a larva destined to become a worker, 

 but converted into a queen, attains with the increased sexuality 

 all the little structural and psychological differences which 

 otherwise distinguish a queen. Regarding fertilisation as a sort 

 of nutrition, he considers drones, workers, and queens as three 

 terms of a series, and the same view is suggested by Rolph. 

 Eimer recalls some interesting corroborations from humble bees. 

 There the queen mother, awakened from her winter sleep by 

 the spring sun, makes a nest, collects food, and lays her first 



