SMALLPOX, SYPHILIS, CANCER, ETC. 203 



same tumour the multitude of large amoeboid parasites 

 lying in intercellular spaces could easily detach portions of 

 the growth and, if the host-cells of the latter had been 

 rapidly dividing, metastases would have occurred. 



Where a melanotic sarcoma of the choroid of the eye is 

 accompanied by secondary growths in the liver, we assume 

 that metastasis has occurred, and so it may be, but not 

 necessarily ; for the parasites may be capable of causing 

 granular pigmentary change in previously unpigmented 

 connective-tissue or endothelial cells. 



In epithelial cancer, as for instance where growths 

 secondary to a cancer of the thyroid are present in the skull, 

 metastasis must have occurred and it is easily explained by 

 the movements of the parasites detaching portions of the 

 tumour into lymphatics or veins and so into the blood- 

 stream to find lodgment in parts best suited to growth of 

 the transplants. 



Conclusions. Before one ventures to formulate con- 

 clusions the real objective position should be clearly defined. 

 In parasitism by common fungi we saw in Chapter II how 

 vast numbers of the parasites perish. The same feature 

 presents itself in syphilitic gumma and in sarcoma. This 

 fact was emphasised in 1901 by Gaylord : " All the organs, 

 including the blood, taken from all regions of all cases dying 

 of cancer, including sarcoma and epithelioma, contain large 

 numbers of the organisms." Fresh teasings reveal the 

 presence of parasites in forms that are concealed by routine 



