258 THE
ENZYME TREATMENT OF CANCER
This
is, of course, really an attempt to place the recapitulation-theory on a
scientific basis. In 1896 the writer suggested a modification of the idea in
proposing to recognize, not so much development by substitution of organs, as
development by substitution of organisms. Kleinenberg’s doctrine is false,
because for every organ, A, B, C, D, E, etc., in the worm, there is not a
corresponding organ a, b, c, d, e, etc., in the larva. If capital letters be
taken to denote the organs of the worm, or sexual generation, and small letters
those of the larva, or asexual generation, the latter may be made up of a, b,
c, d, e, f, g, while the former will be composed of A, B, C, D, E, F, G, H, I,
J, K, L, M, N, O, P. Moreover, A does not replace a, B oust b, and C substitute
itself for c, etc., at various periods of the development, corresponding to the
periods at which this may be presumed (without evidence) to have happened in
the ancestral history; but all the facts go to show that at a certain epoch—the
critical period—A + B + C + D + E + F ± G + H + I + J + K + L ± M + N + O + P
begin to substitute themselves for—i.e., to suppress—a + b + c + d + e
+ f + g, the latter all then beginning to degenerate. These are plain, simple,
elementary facts of development, not to be found in any textbook extant, but
which can be verified easily in a worm, or a fish, or a mammal. For the annelid
they were first really described without the true interpretation by
Kleinenberg; for the fish and mammal by the writer in his published researches.
But clearly a + b + c + d + e + f + g together make up the parts of the larva ;
A + B + C + D + E + F + G + H + I + J + K + L + M + N + O + P those of the
worm. Therefore, the conclusion may be drawn that the worm as a whole, as an
organism, replaces another organism—the larva. Or, in other words, the
development is one of substitution of organisms. But it is something more than
this. The organs of the larva are not homologous with any like-named organs of
the worm, and neither organism as a whole is homologous with the other; and so
this substitution of organisms is in reality an instance of antithetic