870 
Trypanosoma lewisi 
it probable that they are mainly produced by division because active 
reproduction begins only after the formation of the rosettes. We 
suppose that these rosettes are formed by the apparent tendency of the 
large oval forms to adhere to anything, they may adhere to the gut- 
wall but also to one another. This phenomenon is quite different from 
the ordinary agglomeration. Some of the broad forms described by 
Rodenwaldt as “ ookinetes ” resemble our large oval forms. 
Diagram VIII. 
Fig. 1. Rosette of large oval and round forms. G. 
Fig. 2. Rosette of large oval and round forms, slender and thick eritliidiae. I. H. 
Seventh day. On the seventh day we found the number of round 
forms to be larger than on the previous days. The round forms arising 
from the large oval forms at this period are generally larger than those 
found later which arise from the small oval forms (see below). They 
generally possess a large nucleus (Diagram IX) with a well-marked 
Diagram IX. 
Figs. 1 and 2. Dividing and non-dividing round forms. G. 
karyosome. This structure is dividing in Fig. 1, probably previous to 
the nuclear division, although the division of the karyosome is not 
necessarily followed by nuclear division. In Fig. 1 the blepharoplast 
is also dividing, the achromatic substance becoming elongated with the 
