acknowledged in the text of his 'Icones'
the existence of the POSTERIOR CORNU of the lateral ventricle in
the Apes, not only under the title of 'Scrobiculus parvus loco cornu
posterioris'--a fact which has been paraded--but as 'cornu posterius'
('Icones', p. 54), a circumstance which has been, as sedulously, kept in
the background.

Cuvier ('Lecons', T. iii. p. 103) says, "the anterior or lateral
ventricles possess a digital cavity (posterior cornu) only in Man and
the Apes...its presence depends on that of the posterior lobes."

Schroeder van der Kolk and Vrolik, and Gratiolet, had also figured and
described the posterior cornu in various Apes. As to the HIPPOCAMPUS
MINOR Tiedemann had erroneously asserted its absence in the Apes; but
Schroeder van der Kolk and Vrolik had pointed out the existence of what
they considered a rudimentary one in the Chimpanzee, and Gratiolet had
expressly affirmed its existence in these animals. Such was the state of
our information on these subjects in the year 1856.

In the year 1857, however, Professor Owen, either in ignorance of these
well-known facts or else unjustifiably suppressing them, submitted to
the Linnaean Society a paper "On the Characters, Principles of Division,
and Primary Groups of the Class Mammalia," which was printed in the
Society's Journal, and contains the following passage:--"In Man,
the brain presents an ascensive step in development, higher and
more strongly marked than that by which the preceding sub-class
was distinguished from the one below it. Not only do the cerebral
hemispheres overlap and the olfactory lobes and cerebellum, but they
extend in advance of the one and further back than the other. The
posterior development is so marked, that anatomists have assigned to
that part the character of a third lobe; 'it is peculiar to the
genus Homo, and equally peculiar is the posterior horn of the lateral
ventricle and the 'hippocampus minor,' which characterise the hind
lobe of each hemisphere'."--'Journal of the Proceedings of the Linnaean
Society, Vol. ii. p. 19.

As the essay in which this passage stands had no less ambitious an aim
than the remodelling of the classification of the Mammalia, its
author might be supposed to have written under a sense of peculiar
responsibility, and to have tested, with especial care, the statements
he ventured to promulgate. And even if this be expecting too much,
hastiness, or want of opportunity for due deliberation, can