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).