SMALLPOX, SYPHILIS, CANCER, ETC. 191 



appears in the parasite it may have the form of nuclei with 

 achromatic linin fibres. 



Those who from year to year have numbers of malignant 

 tumours to examine will find some in which the parasitic 

 features are as plain as in this mammary sarcoma. In another 

 growth of the same kind I found the intracellular stages easy 

 to be seen, but other stages were hard to see owing to the 

 parasites being in a more labile state. Fresh teasings are 

 required in such cases. In slow-growing cancers parasites 

 are naturally fewer, but with patience they can be found 

 even in rodent ulcer, one of the slowest and least malignant 

 forms of cancer. 



Synchytrium and cancer. On comparing Fig. 23 with 

 Fig. 54 it is seen how closely the larger intranuclear parasites 

 in this sarcoma resemble the nucleolus of the thistle- 

 Synchytrium, presenting club-shaped or more slender knobbed 

 processes from which chromatic substance is differentiated ; 

 a conversion of pycno-plasson into chasmatoplasson or into 

 chromidium. The sarcoma parasites in some cases fuse 

 into plasmodia ; the latter feature is not so prominent as it 

 is in cysts caused by Olpidiiforma, Fig. 46. 



In Fig. 24 ; a, the nucleolus of a Synchytrium is seen to 

 have become amoeboid ; now had such a parasite been 

 reduced to the condition of its nucleolus as is the case in 

 plassomyxines, and had met another in a similar state the 

 two would doubtless have fused into a plasmodium. 



In the choriocarcinoma, Fig. 55 ; 15 to 17 the intra- 



