10 ART. 8. 1. IKEDA : THREE NEW AND 



the male worm of the present species seems to have fallen into 

 a state in which the degeneration of the same organ has gone a 

 step further. This is manifested in the fact that the digestive 

 tract does not exist as a canal but is evidently represented by a 

 large number of separate vesicular sacs, floating freely in the fluid 

 of the body-cavity. In my opinion, the sacs have arisen in that 

 the alimentary tube has undergone division into pieces, which, by 

 closure of the wall at ends, have each assumed a vesicular form. 

 My attention was first called to the vesicles as the male 

 specimen was laid into oil preparatory to imbedding. Under the 

 microscope they appeared as smooth-surfaced, regularly spherical 

 bodies, varying in diameter from 0.2 mm. to 0.3 mm. They were 

 found scattered in the whole extent of the body-cavity, apparently 

 without any definiteness as to the manner of their occurrence. 



Sections showed that the bodies in question are hollow spheres, 

 closed on all sides and bounded by a thin continuous wall con- 

 sisting of two epithelial layers (fig. 17, PI. IL). The outer layer 

 {pr.) is made up of excessively flattened cells arranged in a 

 single row and looks quite like the peritoneal epithelium. In 

 fact I believe it is nothing else than the peritoneal covering of 

 the intestinal wall. The inner layer (ept.) is much thicker and 

 is composed of approximately cubical or cylindrical cells, arranged 

 likewise in a single row. The inner free ends of the cells are 

 generally seen to be produced into a few pseudopodia-like processes 

 of varying length. Frequently the processes send out branches. 

 They may moreover anastomose with those from an adjacent cell. 

 The body of the cells contain a number of large and small 

 vacuoles, which often press aside the nucleus of the cell. The 

 central cavity of the vesicular bodies in question contains no 

 substance that can be revealed by staining. 



