SMALLPOX, SYPHILIS, CANCER, ETC. 175 



had been digested in zoology Calkins (1909) wrote of 

 Cytoryctes : " There is no doubt, however, that the parasite 

 is a species of nucleophaga, and the name karyoryctes 

 must go." 



x-^ MXi'^y& 



FIG. 51. KARYORYCTES. a, various stages in the macronucleus of a 

 Paramaecium ; b, spore -formation begins ; c, spores formed, four 

 escaped into host's substance ; d, group of spores ; e, amoebula- 

 formation, below, " residual body " ; /, reticular body containing 

 points of chromatin. After G. N. Calkins. 



Nucleophaga and Karyoryctes. Now we must consider 

 the question left over from Chapter III as to the position of 

 the parasite described by Dangeard in 1895 under the name 

 of Nucleophaga^ and as to its being homologous or not with 



