CHAPTER
II
THE
EMBRYOLOGY AND ETIOLOGY OF TUMOURS
A.
THE EMBRYOLOGY OF TUMOURS.
The
etiology of tumours is one of the darkest regions of pathology. This is by no
means due to lack of hypotheses, rather to the absence of material basis for
any of those current. It cannot fall within the scope of the work to treat of
anything like all the different ideas at some time or other maintained.*
The
writer’s purpose will be served best by referring only to views as to the
nature of pathological growths, based in some form or other upon embryology.**
One cannot read the writings of the pathologists of the last twenty-five years
without being struck by the un-
* For
these, and their name is legion, see Wolff, Jacob: “Die Lehre von der
Krebskrankheit,” Jena, Gustav Fischer, part i., 1907, and part ii., 1911.
** To account for tumours the two views most
advocated at present appear to be that of “embryonic rests” or displacements,
and that of metaplasy. Under “metaplasy” pathologists understand change in the
character of tissue-cells, even in later life. Both are purely hypothetical,
and each of them has been described as savouring of the miraculous. From the
modern embryological standpoint both of them may be said to be impossibilities.
Regarding “metaplasy,” as little as a man can return to his childhood, so
little can any of the cells of his body take on embryonic characters, or change
their nature. If any one small part of the body can do this, why not grant the
same superhuman power to the whole ?
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