ALIMENTARY CANAL IN THE BEE 517 



The protoplasm of the rectal glands of bees taken m ordinary 

 condition, although granular, is devoid of the inclusions 

 described above (PL 17, tig. 22, d). 



In bringing together these facts, we may speak of the absorp- 

 tive role of the rectal glands, which appears to be correct 

 a priori, on account of the long period during which the faeces 

 remain in the rectum in bees hibernating in our latitudes. The 

 microscopical structure of the tall epithelium of the gland 

 points to a possibility of true glandular processes taking place 

 in it. Below we shall discuss the conclusion according to which 

 the rectal glands present the source of seasonal production 

 of catalase, and the point of development of energetic oxidizing 

 processes which is evinced by the intimate connexion between 

 these organs and the tracheae. 



Physiological Part. 



There are few data in literature regarding the ferments found 

 in the organism of the bee. The first works in this direction 

 were conducted by Erlenmeyer and Planta in 1877. 



The authors named dissected 152 worker- bees separating 

 head, thorax, and abdomen, and infused them separately in 

 glycerine. It was found that all the three extracts converted 

 starch to dextrin and sugar, and saccharose to inverted sugar, 

 the extracts from the head and abdomen being much more 

 active than that from the thorax. The extracts from the 

 head and abdomen also contained a ferment dissolving fibrin 

 of the blood, the latter extract being stronger than the former, 

 whilst that from the thorax produced no effect. 



The methods applied by Erlenmeyer and Planta for the 

 preparation of extracts is of no use at all, since the exterior 

 division of the body of the bee into head, thorax, and abdomen 

 does not correspond at all to the division of the intestine into 

 its characteristic portions. 



In 1912 Petersen, whilst studying a question on the digestion 

 in the bee, also made experiments on the determination of 

 ferments in the digestive organs of the bee. In glycerine 

 extracts from the stomachs of bees the author discovered the 



