PREFACE
“MAN,” writes the learned
and genial Carl Ernst von Baer, “considers himself just as necessarily in the centre
of his mental horizon as of his mathematical one.” When, in the closing hours
of the last day of the nineteenth• century, I wrote this citation in the
original German, as the opening words of the preface of the first of a series
of memoirs upon the history of the germ-cells, I little reckoned that the
controversy regarding their story, which was the final link in the general
principle of an antithetic alternation of generations, would be carried on
around the side-issue— the special case in von Helmholtz’s sense—of the origin,
nature, and scientific treatment of cancer. All of these are concerns of
embryology, for they are problems of reproduction, growth, and the
stereo-chemical processes of life. In the discussion of a similar problem of
embryology—that of parthenogenesis (paedogenesis) or virgin reproduction in
fly- maggots (Cecidomya)—von Baer used the above words. His account of
this discovery of Wagner’s has its special interest in connection with the
present work.
Carl
Ernst von Baer writes:* “ that at first the dis.
* Baer, can Ernst
von: “Uber Prof. Nic. Wagner’s Entdeckung von Larven, die sich fortpflanzen,
Herrn Ganin’s verwandte und ergânzende Beobachtungen und über die Paedogenesis
überhaupt,” in Melanges Biologiques, v., 1865, pp. 203-308; loc. cit.,
pp.
241-243.