206 HENRY LESLIE OSBORN 



left) this may be due to slight differences in level. It is planned 

 to treat certain cj^tological points connected with this epithelium 

 in a later paper so that for the present I will only state that these 

 processes are apparently amoeboid and capable of being projected 

 from the deeper body of the cell or retracted. They are clear and 

 barely stained. They are filled with minute black pigment 

 grains which have been traced to the decomposed blood corpuscles 

 of the heron on which the worm had fed. MTiile the intestinal 

 epithelium in some instances shows the appearances just described 

 there are other cases in which its form is quite different as shown 

 in fig. 14. Here it is a low, level surface consisting of a layer of 

 protoplasm with imbedded nuclei. There are no division walls 

 and the layer has the appearance of a syncytium. Cells of the 

 type shown in fig. 15 are found in the intestine of worms from the 

 bass. I have interpreted them as being in a resting or non-diges- 

 tive state while those in fig. 13 are actively engaged in the work of 

 digestion. In many trematode sections and figures with which I 

 am familiar the cells of the epithelium are entirely distinct and 

 independent to their very base. They do not show any fusion 

 as if syncytial as is the case here. In connection with the struc- 

 ture of Cotylaspis ('04, fig. 19) I called attention to the entire 

 independence of the cells of the intestinal epithelium. ' In Crypto- 

 gonimus, on the other hand, the cells of the epithelium of the intes- 

 tinal caeca are fused into a syncytium. 



The circular muscular coat is very scanty, its fibers lie close to 

 the epithelium. The longitudinal coat is. also very feeble. Its 

 fibers lie at a distance in the parenchyma. 



The cavity of the intestine of the worms obtained from bass 

 cysts is filled with thin, fiat, four-sided crystalline bodies. As 

 soon as the worm has escaped from its cyst the strong peristaltic 

 contractions already mentioned force this substance backward 

 and forward. At frequent intervals portions of it are expelled 

 from the body through the mouth. In worms obtained from the 

 heron this material is not found in the cavities of the intestine. 

 In such worms on the contrary the intestine has been found to 

 contain a coagulated fluid substance with blood corpuscles scat- 

 tered through it, which upon careful examination were found to be 



