ALIMENTARY CANAL IN THE BEE 547 



liition of some kind of excretion. Valle (1900) supposes that 

 ' les papilles rectales des Dipteres joiient deux roles : le role 

 respiratoire et le role secreteur. Role respiratoire par les 

 gros troncs tracheens et les petites ouvertures qui servent de 

 debouches aux raniitications tracheennes ; role secreteur par 

 les cellules geantes et les pores terminaux leur donnant ouver- 

 ture dans la cavite rectale ' (loc. cit., p. 60). 



Thus, Valle unites the views regarding the glandular role of 

 the rectal glands expressed by Lowne (1869) and regarding their 

 analogy to the rectal gills of the dragon-fly larvae (Leydig, 

 Chun, 1876). 



It is quite possible that these organs discovered by 8wam- 

 merdam in the bee play different roles in insects. It is remark- 

 able that the rectal glands are absent in beetles. 



In other insects they appear only at the end of the pupal 

 stage, and only the dragon-flies (Libellulidae) are provided with 

 these glands in the larval stage as well (Paussek, 1887). 

 Evidently these organs, the function of which is mysterious, 

 stand in some connexion with the metamorphosis of insects. 



On comparing these considerations with facts observed in 

 bees its rectal glands may with a considerable degree of 

 probability be regarded as glands one of the functions of which 

 is the seasonal production of catalase. 



Whereas the rectum of the bee is capable of producing 

 a ferment albeit periodically (catalase), its crop lacks this 

 property absolutely. 



No ferments were ever established in extracts from the 

 honey-stomach. This circumstance allows us to take a step 

 nearer toward the solution of the question regarding the process 

 of honey formation. The bee takes in the nectar into the 

 crop from which it deposits it into the honeycombs. Does the 

 crop present a passive reservoir adapted only to temporary 

 conservation of the nectar, or does some other biochemical 

 process, besides the splitting up of cane-sugar, take place in it ? 

 What takes place in the nectar deposited in the honeycombs 

 during the ripening of the honey ? In order to solve this 

 question one of us (E. Zarin) had previously (1917) conducted 



