Tumours appear to arise spontaneously, i.e.
The bark contains a large amount of a fine, highly-resinous turpentine, which collects in tumours on the trunk during the heat of summer.
Melanins obtained from tumours form black, shiny masses; they are insoluble in water, neutral salt solutions, dilute acids and in the common organic solvents.
Some pathological cells, such as the giant-cells of tumours, of bone, and those of tubercle, are polynucleated; in some instances they may contain as many as thirty or more nuclei.
Tumours Or New Growths The various definitions of the term " new growth " leave us with a definite conception of it as a new formation of tissue which appears to originate and to grow independently.