No. 3.] STUDY OF STENOSTOMA LEUCOPS O. SCHM. 275 



At the base of the cell is a large round or ovoid nucleus (Fig. 

 9, N) 1.5 /i in diameter. In the nucleus is a small round darkly 

 stained nucleolus {N}^ which is centrally located. It is .5 /* in 

 diameter. 



When a living worm is slightly compressed, motion which 

 resembles very much the movement of cilia, is seen in the intes- 

 tine. This is best seen in the posterior end, where the intes- 

 tine is thinnest. In sections (Figs. 9-12, P.P) the distal end of 

 the cell is seen to be covered with long, very narrow protoplas- 

 mic processes wider at the base and gradually tapering to a 

 point. In some cases these processes are seen to be run to- 

 gether into a mass (Figs. 9 and 12, X). 



These processes project not only from the end of the cell, 

 but also from a short distance down the sides. When the cells 

 are closely packed together, the processes from the sides of the 

 adjoining cells become so closely matted that they many times 

 fuse and have the appearance of large protoplasmic projections 

 from between the cells. These processes vary very much in 

 size. The most of them are Z [xXo 10 /x long, but some become 

 as long as the cells themselves. 



When the intestinal cells are crushed out of a living worm, 

 they assume a spherical form, with the long processes coming 

 out from one side only (Fig. 10). When first pressed out they 

 move about in the water very rapidly. They soon become com- 

 paratively quiet, and then they may be seen to have withdrawn 

 the long narrow processes, and to undergo amoeboid movement 

 by putting out blunt pseudopodia. When the cells are in 

 this condition, fine particles may also be seen moving about in 

 them. One or more oil-globules which remain comparatively 

 quiet may also be seen within the cell. When these cells were 

 treated with .75 per cent salt solution, they became quiet. When 

 the same solution containing methylin blue was applied to 

 them, the nuclei (Fig. 10, A. and B., N.) of the cells appeared, 

 but no nucleoli could be distinguished. 



In sections of worms which had been treated with chrom-osmic- 

 acetic acid, the intestinal cells were filled with spherical oil- 

 globules which had been colored black by the action of the acid. 

 The large majority of these globules are situated at the distal 

 ends of the cells. They vary greatly in size. Generally there 

 is one 4 /i to 6 /i in diameter in a cell. This large one is sur- 



