80 THE ENZYME
TREATMENT OF CANCER
oma
from a germ-cell of the testis may be cited as an instance of a refusal to
recognize the plain and simple facts of the writer’s researches upon the
germ-cells.
As
further evidence for the origin of embryomata from cleavage-cells (of the
embryo), Wilms refers to the unilateral nature of many of them. This is
supposed to indicate something corresponding to the results of Roux’s
well-known experiments upon the egg-cleavage of the frog, which many years ago
were believed to demonstrate the” prospective destinies “of, say, the first
four products of the cleavage. It must always be difficult to determine what
the researches into so-called “experimental embryology” really demonstrate,
more especially in view of the discrepancies in the results of the different
observers but to most of them it would probably be more correct to apply the
term “experimental pathology,” for the finds border on pathology rather than
upon embryology. Normal larvae of reduced size may have been obtained by such
experiments; normal embryos—Roux’s “hemiembryos” are not such—have never been
a result. Roux’s particular finds probably ensued not because he had
experimentally halved the cleaving germ, but because in trying to do this he
had induced pathological changes. If the hemi-embryomata referred to by Wilms
be hemi-embryos in Roux’s sense, this ought also to apply to the individual
harbouring them. As a matter of fact, it is a pathological change in the
embryomata which induces the halving, as evidenced by several pathological
skate embryos, described by me, in nearly all of which there were marked
reductions, either in the head-end or on one side of the body.
Marchand
and (formerly) Wilms have been disposed to derive the embryomata from
fertilized polar bodies. The writer must emphatically reject this view. Wilms