114 Beekeeping 
digestion. According to Petersen, the peritrophic membrane 
in the ventriculus is so formed as to make regurgitation 
from the ventriculus impossible. 
While the work of Schiemenz and Schonfeld must be 
given due consideration, we must wait until some competent 
investigator takes up this problem. The various arguments 
are thus summarized by Snodgrass (p. 100): 
“1. The brood food itself is a milky-white, finely granu¬ 
lar, and gummy paste having a strong acid reaction said to 
be due to the presence of tartaric acid. 
“2. The pharyngeal glands of the head are developed in 
proportion to the social specialization of the various species 
of bees; they are always largest in those individuals that 
feed the brood, and they reach their highest development 
in the workers of the honey bee. From this it would seem 
that they are accessory to some special function of the 
worker. 
3. The contents of the stomach in the workers consist 
of a dark brown, slimy, or mucilaginous substance in no 
way resembling the brood food, even when acidulated with 
tartaric acid. Pollen is present in varying quantity, mostly 
in the posterior end of the stomach, and shows little or 
no evidence of digestion. Since the brown food is highly 
nutritious, it must contain an abundance of nitrogenous 
food material, which is derived only from pollen in the bee’s 
diet. Therefore it is not clear how the stomach contents 
can alone form brood food. 
“4. The constituents of the food given to the different 
larvae, at different stages in their growth, and to the adult 
queens and drones show a constant variation apparently 
regulated by the workers producing it. A variation of .this 
sort cannot be explained if it is assumed that the brood food 
is produced by the glands alone. 
“5. Powdered charcoal fed to a hive of bees appears 
after a short time in the brood food in the cells, and this 
has been urged as proof that the latter is regurgitated ‘ chyle.’ 
But it is certainly entirely possible that the charcoal found 
