144 



LECTURE VI. 



With, the extension of the cranial basis, which also obtains 

 in the gorilla, — in which, according to Owen, the sella turcica 

 is less depressed than in the chimpanzee, — is undoubtedly con- 

 nected the internal capacity of the skull. The occipital fora- 

 men, as well as the minor apertures through which the cranial 

 nerves pass, are all larger in proportion to the cranial space 

 than in man ; a natural consequence of the greater size of the 

 spinal cord and the nerves in proportion to the cerebral hemi- 

 spheres. 



The internal cranial capacity and certain of the chief measure- 

 ments are, according to Owen, as follow : 



Length of SkuU 



Length of cerebral 



space 



Height of cerebral 



space 



Contents of cerebral 



space in cubiij 



inches 



English- 

 men 



In. lines 

 7. 4. 



6. 6. 



5. 6. 



96 



Malay. 



86 



Negroes 



Austi a- 

 lians. 



82 



In. lines 



8. 0. 

 6. 3. 

 5. 



75 



Gorilla. 



Orang. 



In. lines In. lines 

 11. 10. 9. 0. 



5. 1. 

 3. 3. 



30 



4. 3. 

 3. 5. 



28 



Chim- 

 panzee. 



28 



Despite the equality in height which may exist between the 

 gorilla and the Australian, the cranial capacity is one and a 

 half times larger in the latter than in the former ; a proportion 

 so much the more favourable for the Austral Negro, as in the 

 gorilla the legs are proportionally shorter, and consequently 

 the trunk larger and more powerful. The limits may, however, 

 be brought closer together ; for the smallest human skull, not 

 idiotic, measured by Morton, had a capacity of 63 cubic inches, 

 whilst the largest gorilla cranium recently measured possesses 

 only a capacity of 344 cubic inches. 



These measurements afford, moreover, an important insight 

 into the relative proportions of the skeletons of the head and 

 face. If we assume the entire length of the skull = 100, and 

 then express the proportion in which the length of the cerebral 

 space, that is to say, of the brain itself, stands to the length of 

 the skull, we obtain the following numbers : Europeans =89'1; 

 Austral Negroes = 78'7; orang = 47"7; gorilla = 45"9; whence 



