SKELETON OF BIMANA. 



571 



392 



the proportion of the cranial 



The progressive superiority of the cranial over the facial 

 division of the skull is best illustrated in the Mammalian class ; 

 but, to show the full gradational extent of diversity, two exam- 

 ples, in this retrospective summary, are borrowed from lower 

 vertebrate classes. 



In the cold-blooded Crocodile, %. 392, theca\4ty for the brain, 

 in a skull three feet long, will 

 scarcely contain a man's 

 thumb. Almost all the 

 skull is made up of the 

 instruments for gratifying 

 an insatiable propensity to 



slay and devour ; it is the material symbol of the lowest animal 

 passion. ^^.^ 



In the Bird, fig. 393, the 

 brain-case has expanded 

 vertically and laterally, but 

 is confined to the back part 

 of the skull. In the small 

 singing-birds, with shorter beak^ 

 cavity becomes much greater. 



In the Dog, fig. 394, the brain-case, Avith more capacity, begins 

 to advance further forward. 

 In the Gorilla, fig. 395, the 

 capacities of the cranium 

 and face are about equal. 

 In Man, fig. 396, the cra- 

 nial area vastly surpasses 

 that of the face. 



A difference in this re- 

 spect is noticeable between the savage and civilised races of 

 mankind ; but it is immaterial as compared Avith the contrast in 

 this respect presented by the lowest form of the human head, fig. 

 396, and the highest of the brute species. Such as it is, how- 

 ever, the more contracted cranium is commonly accompanied by 

 more produced premaxillaries and thicker walls of the cranial 

 cavity, as is exemplified in the negro or Papuan skull. 



the parts named of the coronal suture caused or conditioned (' bedingt ') the trans- 

 verse contraction of the cranial cavity is not stated. If the mechanical idea prevailed 

 that obliteration of a suture prevented the previously distinct bones being pulled 

 apart, so as to allow, or stimulate, disproportionate growth at the margins of the 

 stretched bones, then we should have expected that the elongation of the cranial box 

 would have been prevented in the direction at right angles to the obliterated suture, 

 producing contraction in the longitudinal instead of in the transverse direction. 



394 



Dog. 



