THE CHIMPANZEE 23 



after a few years or months from the effects of our climate, which generally show 

 themselves in various organic affections, although not, as has been supposed, in the 

 form of tubercular disease of the lungs. 



In all points of their structure the chimpanzees are very closely re- 

 lated to the gorilla, although the latter is now generally referred to a 

 separate genus. Originally the chimpanzees were described under the name of Trog- 

 lodytes ; but since that name has been applied at an earlier date to the wrens, it has 

 now been superseded by the somewhat cumbrous, although appropriate name of 

 Anthropopithecus, This change is, however, not to be regretted on other grounds, 

 since, as the name Troglodytes means a dweller in caves, while chimpanzees are 

 purely forest animals, it is highly inappropriate to them. 



In addition to certain distinctive features in the teeth, such as the relatively 

 small size of the tusks or canines of the males, and the circumstance that the upper 

 " wisdom-tooth " is smaller than either of the two molars in advance of it, chimpan- 

 zees may be readily distinguished from the gorilla by the circumstance that the 

 males are but very slightly larger than the females. Moreover, the skull of the 

 male chimpanzee is characterized by the absence of the enormous bony ridges which 

 overhang the sockets of the eyes in that of the gorilla ; while in the lower jaw the 

 length of the bony union between the two lateral branches is much less than in the 

 latter. In both these respects the chimpanzee is decidedly nearer to man than, is 

 the gorilla ; and a further approximation to the human type is presented by the 

 relatively shorter arms, which in the perfectly upright posture only reach a short dis- 

 tance below the knee. The hands and feet also are longer and more slender than 

 those of the gorilla, as may be seen by comparing Figs. 3-8 with i and 2 of the illus- 

 tration on p. 15. Moreover, as in man, the middle finger is longer than either of 

 the others ; and although there is some degree of variation in the relative length of 

 the thumb in different individuals, as a rule this digit reaches to the base of the 

 first phalangeal joint of the index finger. The male chimpanzee does not appear to 

 exceed five feet in height when full grown, and is thus considerably inferior in size 

 to the male gorilla. 



Dr. Hartmann remarks of the chimpanzees that, although the arched 

 Ch ridges above the eyes " are not so excessively prominent as in a gorilla 



of the same age, they are strongly developed, covered with wrinkled 

 skin, and in this case also there is a species of eyebrow, stiff and bristly, with shorter 

 hairs between. The large, wrinkled lids are furnished with thick eyelashes. A 

 general physiognomical distinction between the gorilla and the chimpanzee consists 

 in the fact that the bridge of the nose is shorter in the latter than in the former. In 

 the chimpanzee this part of the organ is depressed, yet the depression is of a coni- 

 cal and convex form, and is covered with a network of wrinkles of varying depth. 

 In the chimpanzee the interval between the inner angle of the eye and the upper 

 lateral contour of the cartilaginous end of the nose is shorter than in the gorilla. 

 There is also some difference in the form of the nose ; it is on the whole flatter, the 

 tip is less apparent, and the nostrils are not so widely opened, nor so thickly padded. 

 The external ear of the chimpanzee has, on the whole, less resemblance to the hu- 

 man ear, and its contour is larger than that of the gorilla. But this organ varies so 



