12 BULLETIN: MUSEUM OF COMPAEATIVE ZOOLOGY. 



bodies (Plate 3, Fig. 3G), which in most cases are clearly seen to be situ- 

 ated between the cells. Each is usually in contact with the basement 

 membrane or provided with a stalk, or style, which connects it with that 

 structure, and the longer bodies often project as far into the lumen of the 

 coecum as do the surrounding cells, or even farther. Each of the bodies 

 is provided with a definite limiting wall, and contains one or more irregular 

 darkly colored corpuscles. It seems difficult to interpret these bodies as 

 cells ; on the whole they have rather the appearance of nuclei. In all 

 cases they are very uniformly distributed throughout the length of the 

 coeca, which suggests that they might possibly be the nuclei of the 

 epithelial cells. This does not seem probable, since in many cases they 

 are clearly seen to lie between the cells, though of course in places where 

 the cell boundaries are apparently obliterated it is impossible to deter- 

 mine their position in this respect. Moreover, the size of the bodies is 

 such as to render it probable that they are not the nuclei of these cells, 

 for they are often larger than the cells themselves. It has occurred to me 

 that they might be nuclei of the cells from the host which had been taken 

 by the worm into the coeca, where they are undergoing a process of 

 digestion. In the slimy matter which often adheres to the body of the 

 worm there are frequently found cells — probably mucous cells from the 

 host — and immense numbers of nuclei without any surrounding cyto- 

 plasm. Many of these nuclei are very similar to those of the accom- 

 panying cells ; others are more or less modified, but I believe that all are 

 derived from such cells and that their present condition is due to degener- 

 ation. The modified nuclei are very similar in size, form, and appearance 

 to the bodies found among the cells lining the crura, and I think it quite 

 possible that the latter are nuclei of this kind which have been taken in 

 by the worm. However, it seems almost incredible that every worm 

 should have such a supply of them and that they should be distributed 

 throughout the digestive tract with such great uniformity. Besides, if 

 they are simply particles of food in process of digestion, it is difficult to 

 understand why they should be found in such constant and intimate 

 relation to the basement membrane. Furthermore, I have never noticed 

 any indication of such a process of disintegration as might be expected if 

 they were really in process of digestion. A further possibility is that the 

 bodies are parasites, but in that case they would have at least the morpho- 

 logical value of cells ; but, as stated before, it seems impossible to regard 

 them as such. The same objection precludes the possibility of consider- 

 ing these bodies gland cells or otherwise modified epithelial cells of the 

 coeca. 



