50 THE ENZYME TREATMENT OF CANCER
The manifestations of life present themselves under the headings of either form and structure, or function. Embryological research deals largely with form and structure, or, more exactly, with the coming about of these. And as, according to the testimony of pathologists, cancer, when it appears, is something new to the organism, —a neoplasm, a foreign thing, not growing and functioning after the manner of the individual containing it, increasing by cell-division after unknown laws, which appear to defy all law, carrying with it widespread eroding destruction, only comparable to that dealt out by some parasites—the phenomena of cancer would have analogies at least to many such lying within the domain of the embryologist. Cancer is something with a beginning it increases like a developing embryonic germ by cell-division ; it invades territory at first foreign to it, and it differs only from a parasitic organism in the fact that its mode of reproduction is what may be defined as asexual. And thus, while as a rule its cycle is limited to the individual harbouring it, carcinoma is something with for itself an indefinite life-cycle, which is only bounded by the life of its host, but which cannot be carried directly over, by germs or fertilized gametes, to another organism.* That the resemblance between the life-cycle of a cancer and that of a higher animal should be incomplete is natural ; for the former is an abnormal product, and it is in the nature of such to differ in some or other important details from the typical or normal.
The problem of the nature of cancer has long been before the writer in his investigations: in fact, ever since
* It has, however, been shown by Hanau and Wehr to be possible to transplant cancer from one individual—e.g., the dog—to another.