RESEARCH ON THE DIGESTIVE SYSTEM OF THE SCHIZOPODA 57 



When the food and ferments hâve been well mixed, they pass into the 

 intestine behind the médian pièce 5,. 



We hâve no intention, in this work, of discussing the nature of the 

 sécrétions from the digestive glands. 



We hâve treated some of our sections of the digestive gland with 

 iodine dissolved in potassium iodide, and found the ordinary yellow colour 

 distinctive of the proteids. 



Keeble and Gamble hâve shown that the reaction of the digestive 

 gland of Macroinysis is alkaline or acid according to the diurnal or noctur- 

 nal colour. 



We did not find any glycogen. 



The absorption of the nutritive éléments, probably takes place in the 

 mid-gut, where the cuticle is very thin; perhaps the latéral pockets of the 

 pyloric cavity/i. /. /. hâve an absorptive rôle also. 



Intestine. 



The'intestine seems to be simply a canal with an absorptive faculty, 

 and has no ferment glands in its epithelium. 



The longitudinal and circular muscles which surround the epithelium 

 of the intestine, produce peristaltic movements which are readily seen in 

 the living animal. 



After fixation, the waves of contraction are often seen by the form of 

 the food which it contains. 



The contents of the stomach and intestine are always constituted of 

 diatoms and végétal matter. 



P. J. Van Beneden claims to hâve found appendages of small Crusta- 

 cea in the intestine oî Mysis, hence he concludes that the régime of thèse 

 animais is not exclusively végétal. 



His observations, however, were without sections, and he may hâve 

 been misled by small teeth detached from the stomach pièces. 



We hâve never found any other Crustacea in the numerous Schizopoda 

 which we hâve examined and we believe that the occurrence of their remains 

 must be quite accidentai. 



We hâve seen that the anus possesses valvules that can be opened or 

 shut at will, by means of powerful circular muscles and extrinsic bands 

 Connecting the wall of the anus to the external integument. The rôle of the 

 valvules is to rcnder intermittent the évacuation of the excrément. 



