ALIMENTARY CANAL IN THE BEE 545 



in one or another degree upon the process of metabolism in 

 the bee. Such an accommodation is presented by the produc- 

 tion of catalase in the rectum at a period when the bee is in- 

 capable of excretion. The increased production of this ferment 

 stands in connexion with the demands of the organism for more 

 energetic oxidative processes, in which there is not so much 

 need in summer when the intestine of the bee discharges its 

 excrements normally. 



After we have convinced ourselves of the logical necessity 

 of the presence of catalase in the rectum, we must solve the 

 question regarding the place where this ferment is produced. 

 Two possibilities may be discussed in this connexion : (a) either 

 catalase is produced by the walls of the rectum in the bee (local 

 origin of the ferment), or (b) catalase is transported to the 

 rectum together with the food from the anterior portions of 

 the intestine, namely, from the stomach. 



We shall first discuss the latter possibility. In preparing 

 extracts from the rectum the large intestine of the bees was 

 cut ; the faeces falling out themselves, the wall of the intestine 

 washed repeatedly in a fresh physiological solution of common 

 salt. Only after being thus cleaned of its contents the intestine 

 was rubbed up with sand in glycerine. The measure of precau- 

 tion described guarantee to a certain degree the purity of the 

 extracts prepared, and therefore allow one to ascribe the 

 property of catalase production to the walls of the rectum. 



The conclusion set forth is indirectly corroborated by 

 another circumstance. If catalase were transported into the 

 rectum from the stomach with the digested food, we should 

 expect this ferment to be present not only in the rectum 

 (the hindmost portion of the intestine) but in the small intes- 

 tine uniting the rectum with the stomach as well. 



However, catalase was absent in extracts from the small 

 intestine in all cases, notwithstanding the fact that they had 

 been less carefully prepared. This part of the intestine is 

 usually not removed from it, and the extracts were prepared 

 from whole pieces of the small intestine with all its contents. 

 Since the extract from the anterior portion of the intestine 



