CHAPTER XXIX. 



SPOROZOA. 



Cyclospora Caryolytica. Schaudinn in 1902 discovered this 

 organism, which lives as a parasite in the nuclei of epithelial cells 

 of the intestinal mucosa in the common mole. It is ingested in 

 the form of spores, from which the slender young sporozoites 

 escape in the intestine and penetrate the nuclei of epithelial cells. 

 Here the parasite becomes rounded and enlarges, becoming 

 quickly differentiated into either the male or female type. The 

 former type of parasite has numerous refractive granules in its 







f 



? T 



*;> ** 





FIG. 177. Cyclospora caryolytica. A, Male cells within the nucleus of the host 

 cell. B and C, Reproduction by multiple division with final rupture of the host 

 nucleus in (C). (From Doflein after Schaudinn.} 



cytoplasm, while the female type has a clear cytoplasm. The 

 parasites grow rapidly and segment after 4 to 8 hours, the females 

 earlier than the males, and the cells resulting from this segmenta- 

 tion, so-called merozoites or agametes, penetrate new nuclei and 

 go through the same development. Four to five days after in- 

 fection of the mole, the parasites suddenly cease their asexual 

 multiplication. The male parasites, microgametocytes, after 

 rapid multiplication of nuclei, give rise to numerous microgametes 



408 



