142 



Journal of Agricultural Research voi. xxviii, no. 2 



material (Table III, fig. 11). Nelson and Sturtevant {SB) and Lineburg {M) 

 have shown that the change in the composition of this food comes definitely soon 

 after the second day, instead of the fourth day, as stated by Von Planta, after 

 which increasingly large amounts of honey and pollen are fed up until the time of 

 sealing. The larva is fed during this period about as fast as it can ingest the food. 

 From this it is reasonable to suppose that there must be a constant surplus of 

 unassimilated food in the larval intestine until after feeding has ceased. 



Table III. — Percentage corn-position 0/ worker brood food, calculated from Von 

 Planta (40), and on the basis of his assumption of 70 per cent water content 



COMPOSITION OF HONEY 



The average chemical analysis of American honeys has been shown by Browne 

 (9) to be as follows: Moisture 17.59 per cent, invert sugar 74.41 per cent, sucrose 

 1.98 per cent, ash 0.23 per cent, dextrin 2.09 per cent, undetermined 3.70 per 

 cent. Approximately the same percentages have been found by all other workers 

 in this field. The maximum sucrose content of honey is given in American 

 standards for food analysis as 8 per cent, although a few samples have been found 

 with a slightly higher sucrose content. In the utilization of honey as food by 

 either the adult bee or the larva, it may be assumed that sucrose is rapidly 

 hydrolized. In any analysis of the stomach content of the bee larva for sugar 

 content, therefore, after the change in larval food has occurred and when honey 

 enters directly into its composition, it may safely be assumed that a determination 

 of the amount of reducing sugar will indicate the amount of unassimilated sugar 

 in the intestine, since there will be but a small additional sugar content from 

 sucrose, if any of the latter sugar still remains. In determining the sugar content 

 of the whole larva, as was done in most of the present work, it may be assumed 

 that there is a comparatively small amount of reducing sugar in the blood stream, 

 because of the exceedingly rapid transformation of these sugars into fat and 

 glycogen which are known to occur in the bee larva. It is therefore concluded 

 that the sugar found in the whole larva is virtually that which occurs in the intes- 

 tine alone, and this greatly simplifies the work of analysis. 



COMPOSITION OP THE LARVA AT DIFFERENT AGE PERIODS 



The work of Straus (43) on the chemical composition of the worker and drone 

 brood during their different developmental stages gives the results of the metabo- 

 lism of this food, as indicated by the presence of fat and glycogen stored in the 

 so-caUed fat body of the larva (Table IV, fig. 12). He was unable to demon- 

 strate more than a trace of what he terms reducing substances, except in one 

 case in which only a sHght amount was found. He behoves that this is because 

 the sugar of the larval food is assimilated so rapidly, as is indicated in the larval 

 composition by the exceedingly rapid increase in the amount of glycogen and 

 fat until after feeding has ceased. 



