122 
GLAND STRUCTURE. 
demonstrated that it has quite another use. The 
prolongation he found to be an infolding of the mem- 
brane, and at the bottom of the honey stomach there 
was a mouth which opened and closed at the will of 
the insect. When the bee wishes to drive the chyle 
food from the chyle stomach into the cells, it forces 
the stomach mouth up to the oesophagus, as seen 
at Fig. 52, B, and the prolongation unfolds, extend- 
ing the chyle stomach to the oesophagus, making a 
direct communication from 
d to through which the 
food is forced by the com- 
pression of the ch)de stomach 
by its muscles. That this 
is possible Schonfeld has 
practically demonstrated, and 
has shown that the pro- 
Fig- 52* — Diagram of Stomach longation is just the right 
Mouth and Prolongation. purpose. The 
question has, however, been further solved, and 
Schonfeld’s view that brood food is not a secretion has 
been confirmed by its chemical analysis by Dr. A. de 
Planta (132, 133), who found that the food not only 
differed with the various larvae, but also that it differed 
at various stages of their development. He found, 
as Leuckart stated in 1855, that queen larvae were fed 
with an abundance of the same food during the whole 
term of their existence, and that this food is chyle. 
The worker larvae, on the contrary, receive similar 
chyle food the first three days, and on the fourth day 
it is changed, and then the larvae are weaned, for the 
