126 D. H. WENRICH 



Within the membrane the chromatin occurs as small granules 

 scattered upon a fibrous network, and as a caryosome (c) of 

 relatively large size which is usually surrounded by a clear area. 

 The exact number of the small chromatin granules had not been 

 determined, but in the early prophases they are reduced to six, 

 which are paired or split. 



The clear area about the caryosome is sometimes large with 

 a diameter as much as one-half to two-thirds that of the nucleus 

 (figs. 1, 2, 7, 8, etc.). In other instances it is much smaller 

 (fig. 13). In figure 1 the caryosome appears to be double, but 

 this condition is rare. Careful focusing usually discloses fine 

 fibrous connections between the caryosome and the network at 

 the periphery of the clear area (figs. 7, 8, 10, 12). There is no 

 apparent constancy in the position of the caryosome, since it is 

 found at either extremity of the nucleus or in any intermediate 

 position. 



Occasionally there is seen a nucleus like that shown in figure 9, 

 but such nuclei often are accompanied by signs of degeneration, 

 and the condition is regarded as abnormal. 



I have not been able to make out a rhizoplast connecting the 

 nucleus with the blepharoplast as described by Kofoid and 

 Swezy('15). 



The cytostome is an opening at the anterior margin of the 

 body on the side of the major axis opposite the nucleus. This 

 side is usually considered as ventral. The cytostome is not so 

 large as that described and figured for T. augusta. There appears 

 to be a short cavity leading into the interior along the ventral 

 side of the axostyle. 



The blepharoplast is a deeply staining granule, or possibly a 

 pair of granules at the anterior end of the major axis of the body. 

 To it a series of other organelles are attached, as already men- 

 tioned. The nature of this focus of organization is difficult to 

 determine. By some authors it is regarded as homologous with 

 the similarly named structure in some of the simpler flagellates, 

 such as the haemoflagellates, and by others it is assumed that 

 in the Trichonomads it is composite, being composed of a number 

 of granules equal to the number of flagella attached. Martin 



