ditions, gradually pushed back to earlier stages of ontogeny, so that
what is the ultimate stage of one form is the penultimate of the next"
(p. 277). To this argument, Hurst could muster only a feeble, slightly
apologetic, and rhetorical reply.
Recapitulation would fall only when the two laws necessary to its
operation—terminal addition and condensation—became untenable
in theory. In the meantime, neither a catalog of exceptions, nor the
assertion that undisputed facts fit another theory better, would budge
it. Only when Mendelian genetics made terminal addition and condensation
untenable in theory, could T. H. Morgan gain acceptance
for his reincarnation of von Baer's position as " the repetition theory."
Only then could Shumway sound his battle cry—" let us return to the
law of von Baer" (1932, p. 98). Only then could Garstang proclaim in
his gentler way: "Ontogeny is not a lengthening trail of dwarfed and
outworn gerontic stages. Youth is perennially youth and not precocious
age" (1922, p. 90).
Benign Neglect: Recapitulation and
the Rise of Experimental Embryology
The empirical critiques of the first thirty years had not shaken
Haeckel's theory. In 1890, Marshall devoted his presidential address
before the British Association to the biogenetic law, " which forms the
basis of the science of Embryology, and which alone justifies the
extraordinary attention this science has received" (1891, p. 827). And,
in 1893, Bather praised a journal for daring to print Hurst's support of
von Baer's principles against the biogenetic law: "Natural Science is to
be congratulated on the publication of an article so opposed to current
belief . . . for it has thereby shown that it will not burke views simply
because they are unfashionable, but rather that it is ready to afford a
free field to all genuine knights-errant who dare to smite the shields of
By 1914, MacBride was lamenting: "In these days this law is
regarded with disfavour by many zoologists, so that to rank oneself as
a supporter of it is to be regarded as out-of-date. The newest theory
is, however, not necessarily the truest" (p. 49). What had happened in
the twenty years separating Bather and MacBride?
The Prior Assumptions of Recapitulation
As late nineteenth-century science became more mechanistic and
experimental,18 the basic explanatory structure that nurtured the
biogenetic law began to ring with a progressively more archaic sound.