156 D. H. WENRICH. 



found in pellucida. Since then stages in mitosis have been discov- 

 ered in the type in fixed and stained preparations, but are rare, 

 having been noted on only two slides out of the many that have 

 been prepared. Amitosis has not been seen in the type, although 

 in those with expanded nuclei some tendency to a division of the 

 caryosome has been observed. 



The stages of mitosis for the green variety (Figs. 22 to 25), 

 from the slide where they were the most numerous (they were 

 rare even here), seem to be accompanied by transformation into 

 the pellucid variety. The chlorophyll is reduced and the chromatic 

 swellings on the roots of the flagella seem to disappear gradually. 

 The swellings are well shown in Fig. 22, are much reduced in Fig. 

 23, appear to be absent in Fig. 24, but traces can be seen in Fig. 25, 

 a later stage. The surface striae in all four stages are characteristic 

 of the type variety. 



TABLE I. 



A SUMMARY OF THE COMPARISON BETWEEN THE Two VARIETIES. 

 Characters. Type variety. Variety pellucida. 



Body form Cylindrical or cigar- Elongately conical. 



shaped. 



Surface striae Spiral, from left over to Spiral, from right over to 



the right. the left, or longitudinal. 



Flagella Three. Usually four or six. 



Swellings on flagellar 



roots Present. Absent. 



Reservoir Smaller. Larger. 



Color Usually bright green. Colorless or slightly green- 

 ish. 



Nucleus Usually compact ; caryo- Expanded ; caryosome con- 

 some obscured. spicuo'us, often multiple. 



Results in cultures.... Assumed resting state; Failed to assume resting 



multiplied ; persisted 5 state, multiply, or to 



months in one. persist. 



Divisions Rare in host; rapid in Rapid in host by both mi- 

 some cultures. tosis and amitosis; not 



in cultures. 



The mitotic divisions of the nucleus of pellucida (Figs. 27 to 31) 

 differ in no essential respect from those of the type. There seems 

 to be a difference in the case of the flagella, however. A double 

 number of flagella (4 or 6) is already present in pellucida and are 

 merely segregated into the two daughter cells, whereas in the type 

 additional flagella seem to develop during division. In Fig. 24 

 there were two groups of flagellar roots, but only three flagella 

 were seen on the exterior. In Fig. 25 the two groups of flagellar 



