Experimental Investigation into the Pathology of Canver. 305 



The piece of tumour submerged in fluid human placental serum was 

 incubated at 100 F. for 134 days. It is wedge-shaped, about half an 

 inch in longest measurement, and appears now at the end of 134 days 

 quite unchanged ; the serum, moreover, is clear and unaltered. 



Certain appearances presented on microscopic examination by the 

 portions of the tumours which had remained sterile after various 

 periods of incubation at 100 F. are recorded and figured in the 

 ' Pathol. Soc. Trans.,' vol. 39. These consisted in the extrusion of the 

 chromatin from the nuclei in the form of bud-like processes which 

 ultimately appeared to become free of the cells. Similar appearances 

 were observed in sections of cancerous tumours which had not been 

 incubated, but we failed to observe them in normal tissues which had 

 remained sterile on nutrient media, whether incubated at 100 F. or not. 



Transplantation Experiments. Having carried out a large number 

 of bacteriological experiments from the point of view of the possible 

 infectious nature of cancer, it was necessary to proceed with the 

 inquiry in the direction of inoculation or transplantation experiments 

 on brutes with living cancerous tissues. Wild animals are exempt 

 apparently from the ravages of this disease ; but those domesticated 

 not rarely fall victims to it. 



Plan of Experiments. The tumour, immediately after its severance 

 from the body of the patient, was placed in a small incubator at 

 100 F., and conveyed in a cab to the Brown Institution. There it 

 was allowed to stand in a large incubator, while the animal in whose 

 body it was to be grafted was etherised. 



The operation was conducted with strict antiseptic precautions. 

 When the peritoneum had been opened, one of us (S.) took the 

 tumour from the incubator and with a sterilised knife or scissors care- 

 fully removed all superfluous tissue (e.g., breast tissue and fat). The 

 whole tumour was then transferred to tho abdominal cavity, or 

 several portions were cut from it and pushed in different directions 

 with the finger within the peritoneum. In some instances a piece 

 was fixed by fine catgut in the centre of a muscle (e.g., the biceps), 

 the muscular tissue being brought together with catgut over it, and 

 in a third series of experiments portions of tumour with more or less 

 of the surrounding tissues were placed in the subcutaneous tissue or 

 in the subperitoneal tissue. 



We avoided the use of tumours that were ulcerated, for we dis- 

 covered that, even with very slight surface ulceration, the deeper 

 parts of the tumour (even at l or 2 inches distance) gave an 

 abundant growth in a gelatine tube. As a rule, the operation wounds 

 ran an aseptic course, and the animals were not inconvenienced at all. 

 In a few cases in which the tumours were discovered afterwards to be 

 on the verge of breaking down, septicaemia set in, and the brutes 

 were killed with chloroform. 



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