112 THE ENZYME TREATMENT OF CANCER
in
the pre-critical period the staining of the trophoblast cells resembled that of the functional
transient ganglion cells—with methyl-blue eosin they took on an exquisite blue
stain. With the passing of the critical period the cells of the trophoblast, as
Hill has shown for the bandicoot (Perameles), no longer took on the
blue stain, but absorbed ever more and more the red eosin. The like change will
be noticed in the transient ganglion cells of the fish; it is also seen in the
merocytes* of the yolk.
Rather
less than two years ago I really commenced to work at the problems of malignant
neoplasms from their embryological aspects. The starting-point for research
here was obtained from certain results of prolonged investigations into the
mode of vertebrate development. From these it had been established beyond
question that in the normal life-cycle of development in any of the higher
animals there were two generations—an asexual one, the “larva,” or phorozoon,
and a sexual one, “the embryo “—that the former was mainly; if not entirely,
represented in mammalian development by the trophoblast, and that in every
normal development the trophoblast was suppressed by the sexual generation,
its degeneration commencing at the critical period with the completion of all
the parts of the embryo. For the past eight years it had been recognized that
at the critical period a change in nutrition always occurred. In 1902** the
conclusion was advanced that cancer was an irresponsible trophoblast, the
continued and unbounded
* “Merocytes” are
certain curious nuclei, or, perhaps cells, with no particular cell-substance
around them as a rule, which occur in the yolk-sac of many fishes. Often they
are much elongated and branched, due to incomplete cell-divisions (pluripolar
mitoses). Apparently they are asexual structures. The writer has, as yet, not
published all his observations upon these merocytes.
** The Lancet, June
21, 1902, p. 1758.