ALIMENTARY CANAL IN THE BEE 541 



(3) 1 per cent, solution of casein containing in 1 litre 16 c.c. 

 of concentrated hydrochloric acid of specific gravity 1-1'24. 



Test-tubes containing 10 c.c. of this solution and 2 c.c. of 

 extracts of the ferments tested were placed for one hour in the 

 water-bath at a temperature of 38-40° C, after which to their 

 contents a concentrated solution of sodium citrate was care- 

 fully added by drops. 



The methods described produced in all cases similar results, 

 the presence of pepsin being established in the stomachs of 

 the bee and drone, whilst the other portions of the intestine 

 were devoid of it. 



(1) Gelatine with extracts from the stomachs of the bee and 

 drone lost the coagulating property after one to three days, 

 whereas extracts from the remaining portions of the stomach 

 produced no visible influence upon the gelatine in this respect 

 during twenty days, after which the experiment was discon- 

 tinued.-^ 



(2) In test-tubes with extracts from the stomachs fibrin 

 dissolved during one to three days, and in the remaining it 

 did not dissolve after twenty days, after which the experiment 

 was discontinued.^ 



(3) The casein test descrilied also manifested a positive 

 reaction only with extracts from the stomachs. 



The results obtained from our experiments allow us to 

 conclude that the stomach of the bee and drone contains a 

 peptic ferment acting in an acid medium, whereas the crop, 

 small intestine, and part of the large intestine with the rectal 

 glands do not produce this ferment. 



Trypsin. 



For the determination of trypsin we employed : 



(1) 10 per cent, alkaline gelatine, as in the case of pepsin ; 



liquefaction of the gelatine followed after one to three days 



only in extracts from the stomachs. 



^ In order to test the sterility of liquefied gelatinous mixture and the 

 fibrin solution sowing was made in agar, l)ut during throe days at 37° C. 

 no growth was observed. 



NO. 263 p p 



