THE EXTERNAL FORM OF ANTHROPOID APES. 37 



supra-orbital arches there are from ei^ht to twenty, 

 or even more, stiff, scattered hairs, after the manner 

 of eyebrows ; and eyelashes are likewise present. 



In most cases the hair of the true chimpanzee is of 

 a black coh)ur. Short whitish hairs may be observed 

 on the lower part of the face and chin, as well as 

 round the posteriors. Sometimes the colour of the 

 hair is shot throughout with reddish or brownish 

 bhutk. 



The orang-utan, the chief representative of the 

 anthropoids in Asia, differs from the African forms 

 of this group, almost at the first glance, in the 

 height of his skull, of which the fore-part is com- 

 pressed and shortened in a backward direction. In 

 the aged male it is, however, provided with high 

 and erect bony crests, which give a prognathous ap- 

 pearance to the countenance. We take an aged 

 male as the type of our description. 



The furehead is high and erect, not retreating 

 like that of the chimpanzee ; it is open, and has 

 moderately convex frontal eminences. From the 

 centre of the forehead a round or bluntly oval 

 eminence sometimes projects. The supra-orbital 

 ridges are strongly arched, yet not so prominent as 

 that of the aged male cliimpanzee, setting aside 

 that of tlie gorilla. The eyes are not widely opened, 

 nor are their lids large and furrowed, but on the 

 lower lids there are deep wrinkles. The small 

 bridge of the nose is generally much depressed, but 

 sometimes assumes a slightly conical form as it 

 issues from the central longitudinal depression of 

 the face. The end of the nose, further removed 

 3 



