98 PROTISTS AND DISEASE 



including myself in cancer, and by myself in syphilis are 

 nothing more than Virchow's " cells of endogenous origin." 

 In 1851 Virchow summed up his observations thus : " A 

 portion of a large cell with granular contents, perhaps an 

 altered nucleus, the dimensions of which it has, becomes 

 homogeneous and clear like water. This portion has at 

 first a sharp and stout wall, which very soon by the addition 

 of fresh layers is thickened and becomes doubly-contoured, 

 in every way like a cartilage cell." The " granular contents " 

 of the foregoing description agrees with the appearance 

 shown in Fig. 26, 2. The " cells of endogenous origin " are 

 nuclei formed in parasites in the chromidial state, and they are 

 only temporary nuclei comparable, perhaps, to the tropho- 

 nuclei of Plasmodiophoraceae (Chapter VII). They are 

 occasionally seen to form in molluscum-bodies in water- 

 cultures, see Fig. 32. They do not represent a necessary 

 or invariable phase in molluscum, or in cancer, or in 

 Synchytrium ; but what may be termed an optional or 

 alternative phase. 



