574 GORILLA AND MAN CHAP. 



than some Gorillas. But the average is undoubtedly as stated. 

 It is to be noted that there is a correspondence between cranial 

 capacity and size of palate, the correspondence being converse, i.e. 

 the greater the brain the smaller the palate. This applies to 

 Man as compared with his Ape-like relatives, but does not apply 

 so accurately to the Gorilla, which has a more extensive palate 

 than the Chimpanzee ; its " brute development " is much greater 

 than that of the Chimpanzee. Not only is the palate larger, but 

 the molar teeth, slightly different in form, are also larger and 

 stronger. This is so plainly marked that " one may say almost 

 with certainty, that any upper molar tooth over 12 mm. in 

 length is that of a Gorilla, and under 1 2 mm. is that of a Chim- 

 panzee." In the skeleton generally it may be said that the 

 crests for muscular attachments upon the bones are greater in 

 the Gorilla. The nasal bones are more like those of lower Apes 

 in their length, and they have a sharp ridge more marked than 

 in the Chimpanzee, which, however, disappears in aged animals. 

 It is a curious fact that Gorillas often have a "cleft palate," 

 owing to the failure of the palatal part of the palatine bones 

 to meet completely. The general conformation of the skull is 

 less brachycephalic in the Gorilla. 



The limbs show a number of small differences, which are 

 associated with a more completely arboreal life in the Chimpanzee 

 as compared with the Gorilla. The latter is approaching the 

 human way of life. In spite, however, of these differences, no 

 hard and fast lines of divergence can be laid down between the 

 two African Anthropoids, for it appears from the many memoirs 

 that have been written upon both that "there is scarcely a 

 feature in any muscle or bone found in one animal which is not 

 also found in the other." The heel of the Gorilla has already 

 been referred to. This is, of course, associated with a plantigrade 

 and therefore non-arboreal mode of progression. Certain of the 

 muscles of the calf of the leg attached to the heel show a more 

 human arrangement in the Gorilla than in the Chimpanzee. It 

 is interesting to find that the muscles of the little toe are 

 diminishing in the Gorilla as in Man. This is most clearly due 

 to terrestrial progression and we may apply the same explanation 

 to Man and ignore tight boots ! The arm of the Gorilla is less 

 adapted to arboreal progression. Its proportions differ from those 

 of the arm of the Chimpanzee in that the fore-arm is shorter. In 



