ALIMENTARY CANAL IN THE BEE 



543 



Table X. Summary Table of Ferments established in 



DIFFERENT PORTIONS OF THE InTESTINE OF THE WORKER- 



bee and Drone. 



Notes. 



+ denotes constant presence of ferment. 

 i denotes indefinite periods of ferment. 

 — denotes absence of ferment. 



Found in the large intestine 

 only during the second half 

 of liibemation. 



Conclusion. 



At the conclusion we shall examine the distribution of fer- 

 ments in the different parts of the ventriculo-intestinal tract 

 of the bee, as adduced in the table above (Table X). 



It is quite natural that digestive ferments should be found 

 only in the stomach of the bee. The latter presents the mid- 

 gut of this insect, i. e. that part of the digestive tract which 

 is developed from the entoderm. Contrary to the fore- (=crop 

 = honey-stomach) and hind-guts (small and large intestines) 

 the stomach of the bee is devoid of an inner chitinous lining ; 

 it is true it is provided with a peripheral membrane (PI. 16, 

 fig. 9, ])) clothing the food masses in the lumen of the stomach, 

 but this membrane is secreted by the entodermal epithelium 

 of the latter and differs in its properties from the chitinous 

 cuticle, being soluble in hydrochloric acid. It is permeable 

 to ferments, and, according to Petersen's experiments, even 

 contains them in its own substance. The fact that ferments 

 are produced only in the mid-gut of the bee is fully in accord- 

 ance with the phenomena observed in other insects. In all 

 arthropods the chief digestive processes take place in the mid- 



P p 2 



