ALIMENTARY CANAL IN THE BEE 521 



intestine produces it continuously during the whole year, 

 whereas in the rectum it was observed in our experiments only 

 in spring. 



The latter circumstance is explainable by the fact that the 

 bee remaining in the hive during the six winter months does 

 not discharge its excrements and retains all the faeces till the 

 first spring flight. The discharge of catalase in the rectum 

 depends upon the accumulation of the faeces in it, and evidently 

 serves as a regulation of the different oxidizing processes and 

 destroys the surplus of peroxides in the intercellular meta- 

 bolism. On the day when the bees issue forth from the hive 

 after hibernation, after three hours of flight during which 

 they become evacuated, the catalase is contained in the large 

 intestine only in a small quantity, and after two days it dis- 

 appears altogether, as is seen from experiments no. 8 and 

 no. 9 in Table 11. 



It would be interesting and important from the practical 

 point of view to ascertain the relations presented by catalase 

 in the southern races of bees, which hibernate for a very short 

 period in comparison with our northern bees. 



It may be supposed a priori that in the rectum of the 

 southern bees less faeces are accumulated than in northern 

 bees, and that the oxidative processes in the former proceed 

 at a different rate from those in the latter. It is possible that 

 respective investigations would provide an explanation of the 

 failure to acclimatize southern bees in the north. The latter 

 on arriving in the north encounter unusual conditions of 

 a long winter, and have therefore to accumulate excessive 

 masses of faeces in their rectum. It is natural that these 

 bees, unaccustomed to such conditions, are liable to different 

 diseases, amongst which pernicious diarrhoea plays the first 

 role. 



In order to ascertain whether the secretions from different 

 parts of the intestine stimulate each other when mixed together, 

 catalase was determined in all possible combinations of extracts 

 from parts of the intestines ; in each separate case 2 c.c. of the 

 extracts named below were taken : 



