104 THE ENZYME TREATMENT OF CANCER
germ-cells destined for the sexual organs of the individual. A malignant neoplasm, due to the spontaneous development of such a retrograde germ-cell, which in the days of long ago would have given rise to an identical twin, has lost to a greater or less degree those potentialities, those unconscious memories, which would have permitted it to complete the full life-cycle of normal development, ending in the formation of a normal embryo. The memories which it retains condition the character of the tumour to which it will give rise, and it is these rudimentary memories, stimulated by its environment in some particular organ, which result now in a sarcoma, now in a carcinoma, mimicking the structure in which it lies. This explains why in one development a certain germ-cell will produce an identical twin, while the corresponding germ-cell in another instance develops into a monster, or into an embryoma, or into such with a malignant tumour, or into a mixed and malignant neoplasm, or, lastly, into a simple sarcoma or carcinoma. All depends upon the amount of unconscious memory retained by those retrogressive germ-cells, which formerly gave birth lo normal embryos, identical twins, triplets, etc. Nay, one may safely take a further step in the like direction. Chorio-epithelioma, a deadly form of cancer in pregnancy, usually rises in instances where either no embryo has been formed (hydatid mole), or it has been aborted at the critical period* as a monstrosity. Is it at all unlikely that here, for some reason or other, either the wrong germ-cell had developed, or, at any rate, that such a one had early usurped the place of the developing
* For a full account of the “critical period” and its peculiarities see J. Beard, “Certain Problems of Vertebrate Embryology,” 1896, and “The Span of Gestation and the Cause of Birth,” 1897, both published by Gustav Fischer, Jena.