740 THE POPULAR SCIENCE MONTHLY. 



width in different individuals, and often terminates on its inner edge 

 in the projecting peaked excrescence described by Darwin, of which I 

 shall have more to say presently. The anti-helix, tragus, and anti- 

 tragus, and the cleft which lies between these two latter parts {mcisura 



inter tragicd) are generally fully devel- 

 oped ; the lobule is more rarely pres- 

 ent. Individual variations in the special 

 structure of these parts may frequently 

 be observed. 



The strong trapezoid muscles are 

 prominent on the neck, and when the 

 head is stretched they stand out like 

 pillars on the sides of the neck. Owing 

 to the great development of the spinous 

 processes of the cervical vertebrjE, and 

 of the muscles attached to them, and 

 to the occipital bones of the skull, the 

 neck is very powerful, almost like that 

 fig-s.-earopaMaleAdultGoriixa. ^f ^ ^^jj^ r^^^ shoulders are remark- 

 able for their breadth, and the pectoral muscles for their large size. 



On the upper and forearms the plastic form of the strongly devel- 

 oped flexor and extensor muscles is very apparent, testifying to the 

 enormous strength of the upper extremities. The hands are large, and 

 very wide, with short, thick fingers. The thumb, of which the ex- 

 tremity takes a conical form, is short, extending little beyond the mid- 

 dle of the second metacarpal bone. The extremities of the otherwise 

 broad fingers are somewhat laterally compressed. The fore-finger is 

 not materially shorter than the middle finger. The third finger is 

 sometimes shorter than, sometimes of the same length as, the first, and 

 the fourth is decidedly shorter. The back of the wrist is covered with 

 deep oblique folds. A net-work of wrinkles, oblique or curved, also 

 covers the skin on the back of the fingers, on which there are callosities 

 up to the first joint. The gorilla closes the fingers when going on all- 

 fours, and turns the back of the hand on the ground, thus producing 

 this thickening of the upper skin on the joints. Callosities of the same 

 nature, although not so extensive, are not rare on the second finger- 

 joints. The palm of the hand is covered with a hard, horny skin, 

 generally beset with warts, especially at the roots of the fingers. In 

 spite of the blackness of the skin which covers them, these character- 

 istics are still apparent. 



The fingers are united by a strong web, reminding us of the mem- 

 brane found on the otter and other web-footed animals, and reaching 

 nearly to the first finger-joint. A thick coat of hair extends to the 

 root of the fingers, although on the backs of the fingers there are only 

 a few isolated hairs. 



The trunk of the body of a gorilla, seen from behind, somewhat 



