The application of an infusion of violet leaves was at one time believed to have the power of reducing the size of cancerous growths, but its use is now discredited.
From these experiments it is shown that cells taken from these growths and introduced into animals of the same species give rise to a cancerous growth, whose cells have acquired unlimited powers of proliferation.
Not only is this true of epithelial cells, but - the connective tissuecells of the supporting structure of cancerous growth, after repeated transplantation, may become so altered that a gradual evolution of apparently normal connective tissue into sarcomatous elements takes place, these giving rise to " mixed tumours."
Many cancer-parasites have been described in cancerous growths, including bacteria, yeasts and protozoa, but the innumerable attempts made to demonstrate the causal infective organism have all completely failed.
- Secondary cancerous growth in heart wall.
The commonest form of malignant tumour is the result of the growth of cancerous elements which have been brought to the liver by the veins coming up from a primary focus of the large intestine.