70
THE ENZYME TREATMENT OF CANCER
Cohnheim
theory of embryonic rests,* and the descriptions and classifications of the
tumours usually adopted have no embryological groundwork whatever, proceeding,
as they do, from the simple to the complex, instead of from the most
complicated teratomata—the embryomata of Wilms―to the simple tumours
represented by but one tissue—a “connective tissue” or an epithelium.**
The
“rest-theory” of Remak-Cohnheim, and their followers is a natural corollary of
epigenesis as the mode of the development; and so little as the possibility of
this mode of development can be admitted, as little can the existence of such
rests of embryonic tissues, organs, or structures, be allowed.*** With the
rejection of the Remak-Cohnheim theory, the modification suggested by Ribbert
also falls to the ground. If the embryo be not gradually built up from a pile
of material, as a house is erected, there can be no superfluous bricks or other
structures to fall back upon as the seed of later tumours. Even were the
development epigenetic—and this is certainly not the case—the actual existence
of such rests has never yet been demonstrated; nor is it shown by the
occasional appearance of a supernumerary or accessory organ or structure, such
as an extra kidney, thymus,
* The theory of
“embryonic rests” as the source of tumours is almost invariably attributed to
the pathologist Cohnheim. As shown in another chapter, it was first enunciated
by the embryologist Remak, and for this reason and for clearness it will be
referred to in these pages as the “Remak-Cohnheirn” theory.
** To his knowledge Wilms and C. P. White are the only authors who, like
the writer, regard the neoplasms in this “inverted” fashion. It may help to
support their attitude in this important matter to add that the writer arrived
at the conclusion that, as a rule, the tumourts were approached in the wrong
order, before seeing their writings.
*** The recognition of the impossibility of epigenesis as the mode of
the development was first made by Weismann in his “Gerrnplasrn” (1893).