620 W. S. PERRIN. 
ones sometimes hyaline (fig. 20) and sometimes foamy (fig. 
35). Granules appear to be absent, but large masses of a 
mucoid-looking substance are occasionally enclosed by the 
trophozoites. 
In many cases differentiation of the trophozoite into a 
denser, more deeply staining, external region or ectoplasm, 
and an internal, more fluid, and vacuolated region or endo- 
plasm is well marked (figs. 25, 34, 35). Pseudopodia are 
frequent, and generally lobose and rounded (fig. 34), though 
elongated and pointed pseudopodia also occur. The pseudo- 
podia are, as a rule, formed from the ectoplasm alone, and 
probably serve to attach the trophozoites to the surface of the 
cells of the Malpighian tubules. 
The nuclei are of two kinds, one which stains a bright red 
with Giemsa and feebly with hematoxylin, and one which 
stains a deep purplish red with Giemsa and very deeply with 
hematoxylin (figs. 9,10, 31,35). The deeply-staining nuclei 
are frequently contiguous to a small area of protoplasm 
staining bright blue (fig. 10). They appear to be composed 
of degenerating substance, since the residual nuclei of the 
pansporoblasts, which are sometimes at first bright red (fig. 
14), stain a deep purple as the spores mature and their own 
degeneration becomes more advanced. ‘The nuclei, which 
stain a bright red with Giemsa, are generally reticular, 
though not infrequently compact. In fig. 11 the nuclei are 
compact, in fig. 15 reticular. Division of the nuclei appears 
to be effected by simple fission (fig. 4). 
AUTO-INFECTIVE Metuops oF REPRODUCTION. 
Multiplication of the trophozoites within the host takes 
place in four ways: 
(1) The young uninucleate trophozoite may divide amito- 
tically into two daughter cells (figs. 50 and 51). 
(2) The nuclei of a young trophozoite may multiply 
amitotically, and proceed to the periphery of the cell (figs. 
