78 THE ENZYME TREATMENT OF CANCER
mammals,
the occurrence of vagrant ones in various parts of the body, skin, pericardium,
pylorus, rectum, liver, kidney, etc., would be as common a phenomenon here as
in the fishes.
The
germ-cells of vertebrates generally are, since 1900, beginning to be
regarded as undoubted products of the egg-cleavage.* Since Wilms, Bonnet,
Marchand, and Borst consider certain teratomata, at any rate, to be the
offspring of cleavage-products, there would appear to be an identity between
their conclusions and my own in this respect. Nothing could well be farther
from the true facts. Taking Wilms as the leading exponent of the one side, the
divergences between the two views work out as follows
By
Wilms and others certain tumours, not by any means all, are referred to
cleavage-cells, not identified as germ-ce11s, but really destined to form some
part of the embryonic body. These cleavage-cells are “ shunted” from the normal
connection at some very early, but not defined, period of the development. As
so derived, they are parts of the organism in which they occur. Against the
above, the writer’s conceptions may be stated in the following
Most,
if not all, true tumours are pathological manifestations of some portion of a
life-cycle, and they are due to abnormal attempts at development on the part of
aberrant germ-cells, derivatives of the cleavage, and destined, not for the
embryonic body, but for future generations. Such vagrant or persistent
germ-cells are the sister - cells of the one by whose unfolding the “embryo” or
individual arose, and, developing pathologically alongside and within another
(sister) form,
* Compare the
recent monographic works on Embryology by Korschelt und Heider, and by
Waldeyer.