THE EMBRYOLOGY AND ETIOLOGY OF TUMOURS 87
as
in them, there are, according to Wilms, all transitions down to the simplest,
these latter being sarcoma (cancer, or asexual generation). (7) Mixed tumours
of the breast, kidney, cervix, uterus, vagina, and parotid. These are
sometimes, not often, two-layered (epidermis), and they are usually made up of
tissues, which can best be described as sarcomatous (cancer, or asexual
generation).
B. THE ETIOLOGY OF TUMOURS.
The
foregoing really forms a continuation and extension of the section on “Dermoid
Cysts and Teratomata,” in a memoir* published by me some years ago. On p. 671
it was written, “How, it may be asked, shall one limit the possible reduction
of an embryoma? Where shall the line be drawn ?“ The present chapter
offers an answer to that question. As the writer suspected in 1900, no line
can be drawn between an embryoma and a simple tumour. In this connection,
apart from the references to the writings of Wilms, it may be of interest to
quote from another writer and able pathologist, L. Pick.** On p. 1193, in discussing the
bearings of his finds, Pick writes: “As I have already shown elsewhere,
it would be false to identify in an embryoma that which, of sorts of tissue or
organs, is finally preserved with that which was originally laid down in it in
the germ. We know that here occasionally only a certain kind of tissue attains
development, that alongside this all other tissues wither in their
development—indeed, completely vanish—or by the one-sided tumour-like growth
* Beard, J.: “The Germ
Cells,” part. i., Raja batis, in Zool. Jahrb., Anal. Ableil., 1902,
vol. xvi., pp. 615-702 loc. cit., p. 669.
** Pick, L.: “Zur
Kenntniss der Teratome: Blasenmolenartige Wucherung in einer ‘Dermoidcyste’ des
Eierstocks,” in Berliner kiln. Wochenschr., Dec. 22, 1902, pp.
1189-1193.