THE PROBLEMS OF CANCER 99
they represent a real conjugation, the preparations ought to carry conviction to the minds of embryologists and cytologists, such as, to name three Wurzburg ones, Stöhr, Schultze, and Sobotta. This is improbable, for the true nature of the preparations shown last July* at Oxford appears to me to be fairly clear.
Very common among pathologists is a modification of the Remak-Cohnheim theory of embryonic rests as the basis of neoplasms. This doctrine of “shunted germs,” only possible under the erroneous dogma of epigenesis, has many followers, especially in Germany. The apparent manifold variety of the malignant tumours, which fortunately is not real, led to the conclusion that they were made up of embryonic or somatic cells; that, for example, a primary cancer of the liver or kidney was composed of liver or kidney cells, and so on. The embryological Conclusions to be advanced here, and which are based on research, do not permit of that explanation. A malignant tumour is such in virtue of the facts, among others, that its cells are not embryonic (though they may mimic such, or even resemble no other cells in the human body), and, that, like cells of the trophoblast or chorion of normal development, the neoplasm eats or erodes its way through other structures, even through living bone. On the other hand, a benign tumour does consist solely of somatic or embryonic cells. Its tissues are normal in structure, for it is a true embryoma, or more or less rudimentary embryo, in Wilms’s sense. A neoplasm is, in short, a futile attempt to repeat a greater or less portion of the cycle of normal development. A true embryoma recites merely some greater or less piece of the embryonic portion; a pure cancer or sarcoma—for these are one and the same thing under different disguises—may attempt