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528 FE. A. MINCHIN AND H. B. FANTHAM. 
are granular protoplasmic masses of; irregular or even 
amoeboid contours, enveloped in a hyaline membrane, and 
probably multinucleate (figs. 2,3, 4). These bodies represent 
the early trophozoite stage, and occur: in the submucous 
connective tissue, as do all other forms of the parasite, a few 
fully developed forms being also seen in the epithelium. 
(2) The parasite increases in size, its hyaline envelope 
becomes thicker, forming a definite cyst-wall, and towards 
the centre of the body the protoplasm becomes segmented 
into spherical masses, each with a single nucleus and a 
delicate membranous envelope (fig. 5). As these bodies are 
destined each to give rise to numerous spores, they may be 
termed pansporoblasts, aword in use for the similar struc- 
tures in the Neosporidia. Formation of the pansporoblasts 
goes on continually from the centre towards the periphery at 
the expense of the peripheral zone of protoplasm, which is 
at the same time growing and causing the cyst to increase in 
size as a whole. 
(3) The pansporoblasts give rise to minute spores in their 
interior, first to one or two, then to a gradually increasing 
number, till about a dozen are found in each pansporoblast, 
forming a spore-morula (figs. 6,7, and 10). The spores are 
minute rounded bodies, each with a single nucleus (figs. 7 and 
10). The oldest pansporoblasts are towards the centre, the 
youngest at the periphery, thus forming the three zones de- 
scribed above. The peripheral zone of protoplasm becomes 
reduced to the vanishing point, and as the cysts do not 
exceed a certain size, it is perhaps used up entirely in the © 
formation of pansporoblasts. 
(4) In many cases it is evident that the cysts burst and 
scatter the spore-morule in the surrounding tissues. It is 
highly probable that this represents the usual method of 
endogenous reproduction of this parasite, both on account 
of the very great number of cysts present in the tumours, and 
from the tendency of the tumours to recur after extirpation. 
Thus in the original growth removed by O’Kinealy signs of 
recurrence were observed in less than a month after the 
