The infectivity of cancer : a retrospect and a forecast / by D'Arcy Power.

  • Power, D'Arcy, Sir, 1855-1941.
Date:
[1895?]
Catalogue details

Licence: Public Domain Mark

Credit: The infectivity of cancer : a retrospect and a forecast / by D'Arcy Power. Source: Wellcome Collection.

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    animals, the source of the cancer being either human or ani¬ mal, the animal carcinomata being derived from the same or other species. The experiments have failed with very few exceptions. Hanau’s experiments at Zurich are well known. He grafted a squamous-celled epithelioma from one rat into the tunica vaginalis of another, and the second rat died within three months with cancer of the peritoneum. This experiment appears to have been more free from fallacy than many other successful cases which have been reported, but it has not proved itself capable of repetition until quite recently, when Dr. Morau claims to have grafted a cylindrical epithelioma from the axilla of a white mouse into other mice, who thereupon developed small hard tumours of a similar structure to that grafted. He concludes from his experi¬ ments that heredity plays a considerable part in the develop¬ ment of cylindrical epitheliomata by affording a suitable soil for their development. He also thinks that new growths vary in their virulence, and became less inoculable from one generation to another. Gestation seems to hasten their evolution. They grow less inoculable and less virulent as they pass through fresh organisms. These conclusions are of great importance, but they need confirmation, and although cancers are tolerably common in animals, yet they are not of every-day occurrence. I should therefore esteem it a very great favour if any of you who come across such animals would send them to me at the laboratories of the Royal Colleges of Physicians and Surgeons in London. They will be immediately and painlessly destroyed, but I shall utilise the growth from which they are suffering. These experiments of grafting upon animals cancer derived from human beings has not been attended by any satis¬ factory results. I believe that the nearest approach to a satisfactory positive result were certain appearances which I obtained after grafting human epithelioma and scirrhus into the irritated vaginae of rabbits. In these experiments, as you will see from the photographs some of you hold in your hands, the small circular bodies found in carcinomata were observed within and between the rabbits’ epithelial cells at the point where the carcinoma had been grafted. I have not yet satis¬ fied myself, however, that these bodies cannot be explained in other ways than by assuming them to be parasites which have crept into the epithelium from an external source. All experiments tend to show that carcinoma cannot be grafted experimentally from men to animals, for the animal cells appear to have the power of destroying human cancerous tissues. It appears, therefore, that experiments in this direction should be made with diseased tissues derived from animals of the same species and not with pieces of car¬ cinoma. Evidence obtained from analogy is always weak, and the explanation of ignotum per ignotius is proverbially bad, at any rate in its naked simplicity, and in science, though it often serves its turn sufficiently well in displays of rhetoric. It is sufficient, therefore, to allude to the singular similarity existing between the appearances met with in cancer cells and those occurring in the blood of patients suffering from malaria. In both cancer and ague the appearances are identical in form and in attributes. It might be that the “ague parasite” and the “cancer parasite” are members of the same family, the one acting upon the blood corpuscles