196 ' THE DESCENT OF MAN. Part I. 
Simiadse. This family is divided by almost all natura- 
lists into the Catarhine 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 Platvrhine 
group or New World monkeys (including two very 
distinct sub-groups), all of which are characterised by 
differently-constructed nostrils and by having six pre- 
molars 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 Catarhine or Old World division ; 
nor does he resemble the Platyrhines more closely than 
the Catarhines in any characters, excepting in a few 
of not much importance and apparently of an adaptive 
nature. Therefore it would be against all probability 
to suppose that some ancient New World species had 
varied, and had thus produced a man-like creature with 
all the distinctive characters proper to the Old World 
division ; losing at the same time all its own distinctive 
characters. There can consequently hardly be a doubt 
that man is an offshoot from the Old World Simian stem : 
and that under a genealogical point of view, he must 
be classed with the Catarhine division . 11 
The anthropomoi-phous apes, namely the gorilla- 
chimpanzee, orang, and hylobates, are separated as a 
distinct sub-group from the other Old World monkeys 
by most naturalists. I am aware that Gratiolet, relying 
on the structure of the brain, does not admit the exist- 
11 This is nearly the same classification as that provisionally adopted 
by Mr. St. George Mivart (‘ Transact. Philosoph. Soc.’ 1S67, p. 300), 
who, after separating the Lemuridre, divides the remainder of the 
Primates into the Hominidse, the Simiadse answering to the Catarhine- 1 
the Cebidse, and the Hapalidas, — these two latter groups answering to 
the Platyrhines. 
