G40 



E. N. PAVLOVSKY 



tube, at the same tinic there (k'Vi'lops in the suctorial apparatus 

 a negative pressure, which causes the liquid matter of the 

 prey, which is squeezed out by the mandildes, to enter the 

 apparatus and fill its cavity (the sucking act). The next 

 moment of feeding is characterized by the relaxation of the 

 second group of sphincters (Text-fig. 11, sj and the contraction 

 of the dilatators (Text-fig. 11, dl,) of the pharyngeal apparatus 



Text-fig. 12. 



Dilatators (dl,) and sphincters (s.,) of pharvnx (fg). Zeiss, DD, 



oc.O. 



(of the middle portion of the fore-gut) ; at this moment the 

 corresponding part of the intestine is strongly dilated. Simul- 

 taneously the levators of the suctorial apparatus (Text-fig. 10, 

 dli) relax and its sphincters contract (s^). As a result the 

 apparatus is closed, and the food which it contained is pressed 

 into the dilated oesophagus (the act of forcing). 



Then sets in the third act of food-taking — the closing of 

 the pharyngeal apparatus (the suctorial apparatus being closed); 

 the relaxing walls of the intestine force the food into the oeso- 

 phagus and the stomach. In this way the larva makes a gulp 

 of food (the act of swallowing). The whole act of food-taking 



