158 



Journal of Agricultural Research voi. xxvm, No. 2 



the percentage concentration in tlie intestine, at least during the progressive feed- 

 ing period, should be approximately five times as great as the value calculated (in 

 Table V) on the basis of the entire larval weight. The calculated percentages 

 for the third and fourth days are now 4.90 and 14.10, respectively, and on the 

 fifth day, just before sealing, the sugar concentration in the intestine should ap- 

 proximate 15.70 per cent (fig. 16). There is, of course, the factor of dilution 





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Fig. 16.-Correlation of time of death from American foulbrood to per cent concentration of reducing sugar 

 m entire larva and to calculated per cent concentration in the intestine. Per cent sugar in the food and 

 per cent glycogen in the larva are shown for comparison 



particularly toward the end of the feeding period, caused by the accumulation of 

 undigested pollen shells, which may lower this figure somewhat. 



Still another approximate check may be calculated from the molecular weights of 

 dextrose, glycogen, and fat, and from the percentage composition of the constitu- 

 ents of the larva (Tables IV and V), in order to obtain the percentage of sugar 

 which was present in the intestine at any one time previous to assimilation neces- 



