are considered: 1, The relative frequency of malignant and benign tumors; 2, the liability of the transformation of benign into malignant tumors; 3, the impropriety of delaying operative interference; and 4, the advantages of early operations.
1. The testimony of careful observors tends to show that the malignant tumors exceed the benign in frequency, and also that many malignant tumors remain stationary and seemingly harmless for one, two, six, eight years, and even for longer periods, then increase rapidly, and soon contaminate the system. (Then follow technical and statistical considerations in substantiation of these propositions.) Twenty-four per cent of all cancerous tumors affect the breast. Benign tumors of the breast are most frequent before the age of forty, and cancerous tumors of the breast are most frequent after the age of forty. Cancerous tumors are very much more frequent in the female than in the male sex. The discrimination of malignant and benign tumors at the bedside is often so difficult that surgeons are justified in advising immediate extirpation and in relying upon the microscope to insure the diagnosis and establish the prognosis.
2. The liability to the transformation of benign into malignant tumors has long been recognized, but the histological demonstration of the phenomenon is modern. It has happened that some tumors have been excised during their transition from the benign to the malignant type, and that this metamorphic process has been verified by careful microscopical examination of different parts of the growths. But so far it has not been possible to determine the precise time of the beginning of the transformation. Warts, moles, and other benign growths upon the face or body have been observed to undergo cancerous metamorphosis many years after their appearance. Fibrous and fatty tumors are often transformed into malignant tumors. So long as a tumor retains a comparatively high degree of organization it remains benign; but when its constituent tissues are disturbed, there is apt to be an accession of tissues of a low grade of organization and the tumor becomes malignant; the lower the organization the greater the malignity.
3. In stating the reasons why he believes it improper and unwise to delay operative measures for the cure of tumors, the author discusses the methods of general and local treatment employed. He considers some of them delusive, and others directly harmful, particularly the escharotics, which he thinks should be condemned. The anciently promulgated precept, that so long as a tumor is causing no apparent mischief and shows no disposition to increase in size it should not be disturbed, is still regarded by many as conservative, and commonly followed to the letter in the management of tumors. In accordance with the light thrown of