DISTRIBUTION OF CLINOSTOMUM MARGINATUM. 



361 



especially in the region dorsal to the heart. They are found here 

 most frequently. They are also found in the ventral wall of 

 the coelomic cavity, in the floor of the mouth between the muscles 

 and the skin and even in the 

 leg between the muscle and 

 the skin. In no case have 

 the cysts been found in the 

 frogs of this region in the 

 interior of muscular tissue 

 surrounded by the fibers as 

 they are so characteristi- 

 cally found in the fish. I . ,../, 

 have as yet not been able 

 to find any reason for this 

 difference in the location of 

 the cysts with regard to the 

 host, but the position of the 

 worm within the cyst is 

 considerably affected, as 

 will be explained fully in a 

 moment. 



The ratio of infection of 

 the frog does not appear to 

 be as high as it is in the 

 fishes studied at Nebish. 

 The percentage of frogs 

 not infected is very high, 

 indeed a large number can 

 be gone through often with- 

 out any cysts being found. 

 The number of cysts in a 

 single individual is usually 

 not large; the frog figured 

 is quite exceptional in that 

 respect. Data for an exact 

 statement on these points are not at present worked out. 



The relation of the worm to the cyst and to the underlying 

 muscle of the body wall is shown in Fig. 9. The muscle fibers 



View of ventral surface after the removal 

 of the ccelomic viscera, showing the numer- 

 ous encysted flukes in place. /, lung; mu, 

 muscles of floor of mouth; p, flukes in place; 

 v, ventral muscles of coelomic cavity; v sk, 

 skin of ventral ccelomic wall. X2/3 natural 

 size. 



