154 " H> WENRICH. 



dozen (Figs. I to 6), they are sometimes much smaller and more 

 numerous especially in individuals which are losing their chloro- 

 phyll. In the cultures these granules often persisted for days or 

 weeks after the protoplasm of the individual of which they had 

 been a part had disintegrated. In the fixed and stained individuals 

 the chloroplasts persist as stained bodies (Figs. / to 9), while the 

 paramylon granules disappear. 



The nuclear conditions in the two varieties are of considerable 

 interest. In the typical green individual the nucleus is compact, 

 the chromatin granules and strands being so close together that 

 they obscure the caryosome (Figs. 7 and 8). The typical nucleus 

 is from one-half to two-thirds the diameter of the body and is 

 laterally placed. In transforming or possibly degenerating indi- 

 viduals the nucleus may expand to conditions approximating those 

 of pellucida (Figs. 10, n, and 20). In the pellucid variety there 

 is a marked tendency for the nucleus to hypertrophy. It expands 

 so as to approximate the diameter of the body and then elongates 

 along the axis. This hypertrophy is accompanied by a multiplica- 

 tion of the caryosome, as many as four having been found in one 

 nucleus (Figs. 12 to 16). Hypertrophy apparently leads to ami- 

 totic division of the nucleus (Figs. 32 to 35), which is probably 

 followed by division of the cell body (Fig. 36). Such arnitotic 

 stages have not been found in the green variety. 



The flagellar situation is somewhat puzzling. In the green form 

 more than three flagella have not been found, although prolonged 

 search has been made. These flagella take their origin from basal 

 granules just behind the reservoir and are separated for their entire 

 length passing through the reservoir, " pharynx," and " mouth " to 

 the exterior. At a point in the reservoir nearest the stigma each 

 flagellar root has a spindle-shaped swelling which stains intensely 

 with haematoxylin. These chromatic swellings seem to be the most 

 constant character possessed by the green variety and in the fixed 

 and stained individuals serve readily to distinguish the type from 

 pellucida, where they are entirely absent. 



In the colorless variety from two to six flagella have been found, 

 but the great majority have either four or six. In a count of two 

 hundred from a single slide 6, or 3 per cent., had two flagella; 7, 

 or 3.5 per cent., had three; 87, or 43.5 per cent., had four; 21, or 



