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600 



MARTIN — DiHClJSSiON ON CARCrNOMA. 



without boing aware of it, overcame in hoiui; way the obstacles thai 

 ordinarily prevent succe.sHt'ul inoculationf Within the last few 

 months a inelauotic sarconui was readily transmitted to a rabbit and 

 in a few weeks had given rise to metastases throughorit the body. 



At all events we are too little familiar as yet with all tlu^ conditions 

 necessary to profluce successful noculations. How many people have 

 already ingest-ed myriads of cholera vibrios by way of experiment 

 and have subsecjuently felt no ill effects ? Our methods at the present 

 day are in many respects imperfect, and failures do not necessarily 

 I'ender the general underlying principles fallible. 



On much that has been written on the contagiousness of cancer and 

 its frequent occurrence in people who live much together I cannot 

 touch, nor of the plausibility of the so-called " cancer-houses," which 

 are marked as being contaminated. I would merely conclude by 

 suggesting that until some other reasonable explanation is aftbrded 

 we are not in a position to despise the parasitic theory of cancer 

 formations. 



It has been 9o often urged, and with apparently great emphasis, 

 that in the majority of cancerous growths there is associated some 

 chronic irritation, it may be a slight and persistent one, that I cannot 

 close without referring for one moment to this theory. Whereas it is 

 true that in a great number of cases some irritant is associated with 

 the development of carcinomata, yet in the vast majority of instances 

 the self-same in*itant may be at work in just the same mild chronic 

 and intermittent way and yet never induce a cancer. Of the number 

 of men who use clay pipes there is surely but a small minority in 

 whom cancer develops on the lip, while in the cases of cholelithiasis 

 how rarely do we find cancerous conditions of the gall-bladder. It is 

 true that with almost every case of cancer of that organ gall-stones 

 are associated, but the mere presence of the cancer, implying as it does 

 some destruction of the epithelium, etc., will supply a most ready 

 nucleus around which concretions can form. Considering, then, hov; 

 common are gall-stones and how rare is malignant disease of the gall- 

 bladder, the latter would seem to be the primary condition and the 

 cholelithiasis a secondary result. The same holds true to a more 

 marked extent perhaps in calculi of the urinary bladder, which, in 

 themselves so frequent, yet only under the rarest conditions are 

 associated with epithelioma of that organ. 



If it be true that chronic mild irritation can stimulate epithelial 

 cells to overgrowths of a malignant type, we have yet to explain why 

 this condition does not more often result from such a pressure. 'Che 

 persistent irritation which produces a clavus never, or scarcely ever, 



