112 



seen as clear oval or round bodies, ^-7^1 in which 

 the distinct and clearly defined pigment occurs. 

 The more advanced forms can scarcely be missed. 

 It is necessary to bear in mind the normal structures 

 and the fact that, until the parasite reaches a 

 considerable size and has a very sharply defined 

 cyst wall, pigment, of the characters belonging to 

 the species of parasite concerned, is present. 



Fig. 32. (Left to right) Pericardial Cell, Fat Body Cell, 



Swollen Epithelium Cell, Thin Membrane shewing 



Sporozoit-like appearance 



1. Zygotes of crescent tertian shew, when 

 young, a clump of pigment resembling black 

 pepper grains (Fig. 33). 



2. Zygotes of simple tertian shew yellowish 

 or golden pigment in wisps (Fig. 33). 



3. Zygotes of quartan shew rather coarse 

 pigment in a clump (Fig. 33). 



The older zygotes (40-60^) are indistinguish- 

 able as regards the species of parasite concerned. 

 They may shew : — 



1. A very clear and distinct cyst wall (ad- 

 ventitious). 



2. The formation of sporoblasts. 



