116 THE ENZYME TREATMENT OF
CANCER
researches,
this is evidently of an (? intracellular) acid nature, like that recorded by
Hartog for the chick blastoderm, etc. Petry’s work is cited in the latest
edition (1903) of Hoppe-Seyler’s “Handbuch der Chemischen Analyse” (p. 387) as
proving the presence of enzymes in malignant tumours.
In
this connection it would be of interest to cite some of the discussions upon “
Extrazelluläre und lntrazellulãre Verdauung’ and upon the enzymes or ferments
in Verworn’s “ Allgemeine Physiologie “ (pp. 161 et seq.). In studying
the history of the yolk-sac of fishes I made many observations upon this
question some years ago. At times one meets with cases in the yolk sac which
are more “ extracellular “ than “ intracellular.” Ultimately, indeed, the
latter passes into the former. In the sequel therefore, the term “
intracellular “ will be used within brackets to indicate not so much its actual
nature nowadays as its origin in past times from a real intracellular digestion
occurring in the presence of yolk. In the chick or skate the yolk is contained
in a yolk-sac ; in a frog, within the cells of the cleavage. None the less, the
ferment is the like one.* The
trophoblast of normal
* It should not be forgotten that, as Verworn
remarks (op. cit*., p. 171) there exists a quite overwhelming
abundance of ferments.” Hartog would seem to assume that the one discovered by
him in the cleaved frogs egg and in the blastoderm of the chick, which must he
common to the asexual generations of vertebrates, is the same as, for example.
the enzyme of the mammalian stomach. For present purposes it is not needful to
insist upon this. Here it will be maintained that this enzyme of
the blastoderm, trophoblast, or malignant tumour can only act in a slightly
acid medium, and that in all probability it is a much weaker one than
that characteristic of the pancreas. The existence of the asexual enzyme
and of the sexual one may account for the necessary existence of
a gastric and an intestinal digestion.
The sexual generation is of later origin in time than the asexual one,
and its evolution has been bound up with that of a new digestive gland and
enzyme, the pancreas, etc.