SPOROZOA, TELOSPORIDIA, COCCIDIA 



281 



zoites produce only six merozoites (j, k) which become the 

 gametocytes {l-o). The gametogony takes place in the leech. 

 Four microgametes are formed from each microgametocyte 

 and become associated with a macrogametocyte in the gut 

 of the leech (p-r). The zygote (s) nucleus divides three times, 

 and eight sporozoites are formed (t-w). 



Haemogregarina are commonly found in various frogs (Fig. 

 119, a-e) and in marine and fresh water fishes (Fig. \\9,f-j)^ 



Fig. 119 a-e. Haemogregarina of frogs. X1400 (After Kudo). 



f-j. Haemogregarina simondi Laveran and Mesnil, from 



the blood of the sole, Solea vulgaris. X1300 (After 



Laveran and Mesnil). f, extra corpuscular form; 



g-j, schizogonic stages in the erythrocyte. 



k. A spore of Hepatozoon muris. X415 (After Miller). 



Genus Hepatozoon Miller. The schizogony occurs in the 

 cells of the liver, spleen, and other organs of vertebrates. The 

 merozoites enter erythrocytes or leucocytes and develop into 

 gametocytes. In blood sucking arthropods (ticks, mites), the 

 microgametes and macrogametes develop and unite in pairs. 

 The zygotes become oocysts which increase in size and develop 

 sporoblasts, spores and sporozoites. 



