gin of Species, a Sketch
written in 1842_. Ed. F. Darwin, Cambridge, 1909.

[353] _Cf._ a parallel passage in the _Origin_, 1st ed.,
pp. 485-6.

[354] In the 1st ed. (p. 439), Darwin makes the curious
mistake of attributing this story to Agassiz.

[355] In which nestlings of the different varieties are
much more alike than adults. Darwin attached much
importance to this idea, see _Life and Letters_, i., p.
88, and ii., p. 338.

[356] See his _Letters, passim_.

[357] Writing to Huxley on the subject of the latter's
work on the morphology of the Mollusca (1853), he
says:--"The discovery of the type or 'idea' (in your
sense, for I detest the word as used by Owen, Agassiz &
Co.) of each great class, I cannot doubt, is one of the
very highest ends of Natural History."--_More Letters_,
ed. F. Darwin and A. C. Seward, 1903, i., p. 73.

[358] Italics mine.

[359] _Das Problem des Lebens. Biologische Studien_. Bad
Sacha, 1906. See also E. Radl, _Biol. Centralblatt_,
xxi., 1901.

[360] See the excellent treatment of the difference
between the "realism" of Darwin and the "rationalism" of
his critics, in Radl, ii., particularly pp. 109, 135.
The most elaborate criticism of Darwinism from the older
standpoint was that given by A. Wigand in _Der
Darwinismus und die Naturforschung Newtons und Cuviers_,
3 vols., Braunschweig, 1872.

[361] In vol. ii. of his _Reden_, St Petersburg
(Petrograd), 1876--_Ueber den Zweck in den Vorgaengen der
Natur; Ueber Zielstrebigkeit in den organischen Koerpern
insbesondere_; and _Ueber Darwin's Lehre_.

[362] "Ueber die Darwinische Schoepfungstheorie," _Zeits.
f. wiss. Zool._, xiv., pp. 74-86, 1864. Elaborated in
_Anat. u. syst. Beschreibung d. Alcyonarien_, 1872.

[363] _Cf._ for instance Naegeli's theory of a perfecting
principle, first developed in his _Entstehung u. Begriff
der naturhistorischer Art_, Muenchen, 1865.

[364] _Anatomy of Vertebrates_, iii., 1868.

[365] _Rapport sur les Progres recents des Sciences
zoologiques en France_. Paris, 1867.

CHAPTER XIV

ERNST HAECKEL AND CARL GEGENBAUR

At the time when Darwin's work appeared there already existed, as we
have seen, a fully formed morphology with set and definite principles.
The aim of this pre-evolutionary morphology had been to discover and
wo