1919.] R- B.S. SeweIvI.: Schistosoma japonicum in India. 427 



The most obvious feature in the body is the large group of 

 five pairs of cephalic glands that occupy the posterior | to | of 

 the body. These glands are pyriform in shape and each cell has 

 a wide and conspicuous duct that runs forward to enter the head 

 gland as noted above. These cells appear to be of two kinds. 

 The anterior two pairs are coarsely granular while the posterior 

 three pairs are finely granular, and each possesses a large and 

 conspicuous nucleus. Cort {I.e., p. 501) makes no mention of any 

 such differentiation in the cephalic gland cells of Sch. japonicum. 

 He states that all five pairs of cells possess acidophilic cytoplasm, 

 as is also the case in the present species. The ducts belonging to 

 the two groups of cephalic gland cells can also be distinguished ; 

 those from the three posterior pairs are large and lie ventrally in 

 a U-shape, while those from the anterior two pairs are small and 

 are situated side by side in the opening of the U on the dorsal 

 side. 



The alimentary canal is extremely reduced. The mouth opens 

 ventrally by a small orifice situated far forward just in front of the 

 junction of the body- wall with the head-gland. A narrow intes- 

 tine passes backwards as far as the anterior two pairs of cephalic 

 glands and there is no trace whatever of any pharynx. 



The excretory system is of the typical Schistosome type and 

 agrees exactly with Cort's description of the excretory system in 

 Schistosoma japonicum. Three pairs of flame cells are situated in 

 the body. Of these the anterior pair is situated laterally, external 

 to the ducts of the mucin-gland canals about midway between the 

 head-gland and the anterior pair of cephalic gland cells. The 

 second pair of flame cells is situated in the interval between the 

 coarsely granular and finely granular cephalic gland cells, rather 

 to the lateral side ; while the posterior pair of flame cells is situated 

 opposite the last pair of cephalic glands. A small excretory blad- 

 der is situated at the extreme posterior end of the body and from 

 this two wide canals pass forwards and outwards, reaching as far 

 forward as the anterior margin of the acetabulum ; they then curve 

 backwards and divide into anterior and posterior branches. The 

 main canal is in two places somewhat dilated and each dilation 

 contains a vibratile flagellum of the same type as the flagella of 

 the flame cells but longer and narrower. The presence of these 

 extra vibratile structures is important as one is very liable at first 

 sight to confuse them with true flame cells and thus to consider 

 the number of flame cells to be five pairs instead of three. The 

 anterior and posterior " collecting tubules " each divide into two 

 branches running to the flame cells. The second branch from the 

 posterior ''collecting tubule " leaves the body and passes into the 

 tail to the fourth pair of flame cells that is situated on either side 

 of the caudal excretory tube close to the root of the tail. The 

 caudal tube enters the posterior end of the bladder by a typical 

 " islet " opening: at the posterior end of the tail the tube bifur- 

 cates, a branch passing along each fork to open to the exterior in 

 a cup-like depression situated at the extreme tip of the ramus. 



