ISOSPORA HOMINIS AND I. BELLI 



the first time; (4) an undetermined species of Eimeria 

 (?) which was discovered by Gubler in 1858" (p. 193). 

 In 1921, Snijders (1921) described oocysts of an 

 Eimeria in human feces which Dobell (1921a) con- 

 sidered a new species and named E. snijdersi. Snijders 

 (1921) suggested that "The cysts might have been in- 

 gested with food or water and passed unaltered (or 

 only slightly altered) through the alimentary canal," 

 and Brug (1922) made a similar suggestion regarding 

 this case because of the native custom of eating intes- 

 tines and livers. The study of oocysts of E. oxyspora 

 (Fig. 17) led Thomson and Robertson (1922) to con- 

 clude that no specific difiference exists between this form 

 and E. snijdersi, and more recently these investigators 

 (1926a) have shown that the oocysts of E. oxyspora are 

 morphologically like those of E. sardince that occur in 

 the testes of sprats and herrings, and the oocysts of 

 E. wenyoni (Fig. 16) like those of E. chipearum from 

 the livers of herrings, sprats and mackerel. Further- 

 more, Thomson and Robertson (1926b) have demon- 

 strated that oocysts of E. sardince may be cooked and 

 eaten without being destroyed and will pass through the 

 digestive tract of man and appear in good condition in 

 the feces. Fish containing oocysts of E. sardines and 

 E. clupeariim are eaten frequently by many people and 

 there seems to be no doubt but that the three species of 

 Eimeria named by Dobell must be considered synonyms 

 of these two species previously described from fish. 



Isospora hominis and I. belli. This leaves one of 

 Dobell's four species, Isospora hominis, to be considered. 

 Wenyon (1923) concluded that there are two species 



189 



