SIMIAD.E. 361 



family, order, or class), the value of these fluctuating characters dimi- 

 nishes ; for it may be laid down as a rule, that the importance of charac- 

 ters increases as we ascend the scale, and vice versa. Hence, in the 

 third sub-family of the Simiadae, the variations of Nature, on one model, 

 ought neither to startle us nor disguise the affinities of the members 

 composing it. 



The arrangement of the sub-families and genera of the Simiadae will 

 stand as follows : 



FAMILY, SIMIADAE. 



SUB-FAMILY I. Genera. 



Tail wanting ; arms long ; general figure anthro- t Troglodytes, 

 poid ; stomach simple ; caecum with vermi- I Pithecus. 

 form appendix. t Hylobates. 



SUB-FAMILY II. 



Tail long; no cheek-pouches; stomach complex: e 



.. ' 1 Semnopithecus. 



figure slender; laryngal sacculi ; no vermi- J r 1 h O\ 



form appendix. (. 



SUB -FAMILY III. 



Tail variable; cheek-pouches; stomach simple; f Cercopithecus. 

 laryngal sacculi variable ; general figure I Macacus. 

 more robust, often massive. V. Cynocephalus. 



SUB-FAMILY I. At the head of the Simiadse is the sub-family con- 

 sisting of the anthropoid Apes ; viz., the Chimpanzee, the Orangs, and 

 the Gibbons ; the mutual affinities of which have not been overlooked ; 

 so far from it, indeed, that, from this very circumstance, much discrepancy 

 is to be found in the arrangement of them by different naturalists, each 

 taking different views as to the value of their distinguishing characters. 

 Thus, for example, the Gibbons, though possessing small ischiatic callo- 

 sities, are included, by M. Geoffrey, together with the Orang-outan, in 

 his genus Pithecus ; while for the Chimpanzee he institutes a distinct 

 genus, under the title Troglodytes. On the other hand, Illiger regarded 

 the Gibbons as distinct from the Orangs, and established the genus 

 Hylobates for their reception, a genus adopted by Cuvier, who, again, 

 refers the Chimpanzee to the genus Pithecus, as an Orang, differing only 

 in the comparative shortness of the arms, and in the absence of an ele- 

 vated forehead, which falls back immediately behind the superciliary 

 ridge. (Cuv. Reg. An. 1829, p.. 89.) 



In the present work, the members of this group are arranged under 

 three generic heads, adopting, for the reception of the Chimpanzee, 

 the term Troglodytes, Geoff, which Cuvier has subsequently applied 

 to a genus in ornithology (the true Wrens). These three genera will 

 therefore stand as follow Troglodytes, Pithecus, and Hylobates ; and it is 

 among the members of these genera that the nearest anatomical 

 approach to the human subject exists. This is exemplified less in 



VOL. I. 3 A 



