THE BONES 53 



spending animal bone. It is the aim of the present work to 

 specify these distinctions and to define the characteristic attri- 

 butes of man. In view of the paramount importance of the 

 skeleton of animals and man it is clear that even the most 

 concise treatise on comparative anatomy demands a relatively 

 large amount of space. 



The Skull. 



A skull in the form of a hard capsule made up of several 

 bones, containing the brain, and connected with the facial 

 bones, is possessed solely by the vertebrates. C. Gegenbauer 1 

 has stated with admirable clearness the relation of the human 

 to the animal skull. He says : " The peculiarities of the 

 organisation of the human body are nowhere so significant as 

 in the skull ". When we bear in mind that the formation of 

 the skull in all vertebrates is determined by its relation to the 

 brain, to the organs of sense and to the upper extremity of 

 the intestinal system, the conditions may be formulated as 

 follows : 



In all animals, the apes included, the ultimate capacity of 

 the brain is attained much earlier than in man, so that the 

 human skull has a considerably longer period in which to 

 develop for the benefit of the growth of the brain. Gratiolet 

 points out as cause of this fact that in the anthropoid skull the 

 closing of the sutures begins in the frontal region, whereas 

 among the higher races of man it takes place first at the sutura 

 parieto-occipitalis. The lower races of man in this respect re- 

 semble the anthropoids. As regards the cavities in the skull 

 for the reception of the higher organs of sense man is by no 

 means superior to the animals, indeed in the development of 

 certain senses he is their inferior. 



While the cranium of lower animals ceases early to grow, 

 the facial bones continue to develop until adult age ; this 

 accounts for the preponderant development of the face in all 

 animals up to the anthropoids, as well as for the still greater 

 development of the teeth, and the masticatory muscles, these 

 latter giving rise, in the male, to a bony vertical ridge (see 



1 C. Gegenbauer, Lehrbtich der Anatomie, and edition, p. 253. 



