Comparative Myology of the Chimpanzee. 353 



mcnt between the muscles of the Chimpanzee and those 

 of man, and with this view have dissected portions of six 

 other Quadrumana of the genera Macacus, Cynocephalus, 

 and Ateles, and several lower animals, using also for com- 

 parison the published or MS. notes of a large number of 

 other dissections. (See list at the end of this paper.) I 

 will speak first of some muscles whose functions are 

 chiefly local, and then more in detail of the muscular sys- 

 tem as adapted to the climbing habits of the Quadru- 

 mana. 



Occipito-frontalis. The apes have been generally sup- 

 posed to possess the power of moving the eyebrows and 

 scalp, which man does by means of this muscle ; in him 

 the two muscular bellies are short, the greater part of 

 the skull being covered by the thin aponeurosis which con- 

 nects them. I have dried and preserved the right half of 

 this muscle from the Chimpanzee which I dissected ; the 

 fleshy fibres are proportionally much longer than -in man, 

 and seem to meet upon the vertex ; the occipital portion 

 is quite fleshy and distinct, but the frontal portion is thin- 

 ner and more closely united with the thick skin, so that, 

 commencing in that region, one might very easily over- 

 look it, as I did at first. Tyson and Traill say they could 

 not find it in their specimens, and no other authors men- 

 tion it, except Prof. Owen, who found it in an Orang 

 [Simia Satyrus), and partly in a Chimpanzee. (4.) There 

 were evidences of it in a Cynocephalus and in the Macaci 

 which I dissected, but I did not trace it in its whole extent. 



The muscles of the ear have been as little noticed by 

 anatomists ; the ear of this specimen had been cut ofi" 

 before I dissected that region, so that I am not positive as 

 to the insertions into it ; but in the places of the Attrahcns 

 and Retrahens aurem were series of muscular fibres con- 

 verging towards the ear, their upper borders touching the 

 lower border of the Occipito-frontalis ; they seemed to be 



JOaRNAL B. S. N. H. 45 AUGUST, 1861. 



