64 THE ENZYME TREATMENT OF CANCER
explanations become superfluous. In certain cases in human development, where either no embryo arises within the chorion, or when the embryo becomes aborted or dies prior to the suppression of the asexual generation, the latter—the chorion—may go on growing indefinitely, and may give rise to what pathologists and gynaecologists recognize to be a form of cancer, placentoma, or chorio-epithelioma (Marchand). For years now I have recognized, and, in homologizing this structure with the larval skin of an amphibian, Hubrecht has gone a long way in the like direction, that the human chorion represents the main portion or whole of the asexual generation here. In certain cases, therefore, we here witness the conversion of the chorion—i.e., of the asexual generation—into a malignant tumour, a carcinoma.
What other proof could be asked for? That this proof of the nature of cancer is not in agreement with accepted views of normal development cannot be set down to the fault of the writer. He holds, and has long maintained, such views to be false and unfounded in fact, and, moreover, it has been attempted to indicate the right way. The arguments and conclusions have been neither refuted nor confirmed, but they have been ignored. But embryologists are living, and have long been existing therein, in a mental universe, where but a tithe of the facts observed are explicable under their views. Under the conception of development as an antithetic alternation of generations—especially as laid down in “Heredity and the Epicycle of the Germ-Cells “*—all the known facts of development fit in, all are capable of easy and natural explanation. And the elucidation of the etiology of carcinoma follows as a natural corollary to the law of the
* Biologisches Cenfralblatt, 1902, vol. xxii., pp. 321-328, 353-360, and 398-408.