The Descent of Man

tion of the Simiadae. This family is divided by
almost all naturalists into the Catarrhine group,
or Old World monkeys, all of which are characterised
(as their name expresses) by the peculiar
structure of their nostrils, and by having four
premolars in each jaw; and into the Platyrrhine
group or New World monkeys (including two
very distinct sub- groups), all of which are characterised
by differently constructed nostrils,
and by having six premolars in each jaw. Some
other small differences might be mentioned.
Now man unquestionably belongs in his dentition,
in the structure of his nostrils, and some
other respects, to the Catarrhine or Old World
division; nor does he resemble the Platyrrhines
more closely than the Catarrhines in any characters,
excepting in a few of not much importance
and apparently of an adaptive nature. It
is therefore against all probability that some
New World species should have formerly varied
and produced a man-like creature, with all
the distinctive characters proper to the Old