592 GEORGE H. BISHOP 



Difference in queen and drone. The difference in the aspects 

 of the fat-body of queen and drone is exhibited chiefly in a lesser 

 portion of visible fat-content in the male. This may be a result 

 of a difference in food. The drone, like the worker larva, is fed 

 at first on partially digested food, but later receives considerable 

 crude pollen. A high percentage of protein, and particularly of 

 nuclein-forming materials, such as pollen yields, jnay be con- 

 sidered necessary in the drone's diet to provide material for 

 building up the testes, which shortlj^ before emergence of the 

 drone have displaced the fat-bod}', and nearly fill the large ab- 

 dominal cavity. At the termination of the larval ingestion of 

 food these organs are present, but slightly developed. Their 

 growth during pupation must be at the expense of the fat-body, 

 which tissue may be expected to have stored up the proper 

 nutrient elements in the proper proportions for that development. 

 The testes, large as they are, must demand a higher proportion 

 of nuclein-forming materials for the development of their sperms 

 than any comparable organs in the worker or queen pupae. 



Difference in different body regions. Xo significant difference 

 in the development of the fat-body cells of thorax and abdomen 

 is discernible until after the disintegration and reforming of the 

 nucleus, and the partial development of the albuminoid globules. 

 At a relatively late period in this development, but before all the 

 globules of the cells concerned have attained the final structure 

 and staining capacity of the typical cell contents, scattering 



and protein, prepared in the midintestine of the 3'omig workers or nurse bees. 

 The worker larvae are fed this material the first three days of their life, after 

 which considerable undigested pollen and honey is added. Investigators have 

 been unable so far to assign an}' other difference in treatment as a necessary 

 cause of the different development of the worker, and this cause seems to be a 

 sufficient one. The question remains whether this difference in the effect of the 

 different foods is due to partial digestion merely or to the extraction or modifica- 

 tion of some constituent of the crude pollen, or honey, which, when fed the worker 

 larva without modification, retards or modifies its development. Considering 

 the fact that pollen, the chief protein-containing constituent of the larval food, 

 contains a high percentage of nuclein, it seems possible that some constituent 

 of nucleic acid, such as purines, may be modified or extracted from the queen's 

 food, and left in the larval metabolism of the worker to modifj' the development 

 of the imago. 



