68 THE ENZYME TREATMENT OF CANCER
doubted tendency on the part of, at any rate, many of them to assign some sort or other of embryological basis to very many, if not all, tumours. I should be the last person in the world to deprecate this, convinced as I am that far more tumours than almost any pathologist now living possibly imagines to be explicable embryo-logically have such a basis. I only differ from many pathologists in regarding these neoplasms from an embryological standpoint which is as strange to them as it is to the majority of embryologists. The pathologist who is an exponent of a developmental etiology of tumours naturally endeavours to bring them under the laws of embryology, as given in current textbooks. Since my work of many years past has clearly brought home to me the erroneous, baseless, and impossible nature of many of the tenets and doctrines of modern embryology—e.g., direct development, somatic origin of germ-cells, and epigenesis—it must, of course, be equally clear that an “embryology of tumours” founded on these can only be fallacious.
A tumour, whether simple or complex, is a living thing, and, like everything living, it comes gradually into being, it unfolds and manifests itself, and in this way it has its own developmental history. This statement may appear somewhat metaphorical, but its meaning is clear enough if it be said that very many tumours, from the most complicated teratomata down to cancer (carcinoma and sarcoma), are but bizarre manifestations of some portion of an animal life-cycle. The truth of this could not become apparent hitherto for two reasons: on the one hand, the views maintained as to the normal cycle of development were erroneous; and, on the other, the true science of embryology is as yet almost a terra incognita to pathologists. But, just as there is a science of normal