IN RELATION TO THE ARCHETYPE. 219 



confluence and concealed position even in some fishes — 

 xi2)hias, e. g. — and repeat the character in all mammalia 

 and in most birds; but they become partially exposed in 

 the ostrich and the batrachia. The spine of the nasal 

 vertebra (nasal bones) is usually bifid, like those of the 

 two succeeding segments;- but it is much less expanded. 

 The haemal, called " maxillary" arch, is formed by the 

 pleurapophyses (palatines) and by the h^emapophyses 

 (maxillaries), with which the halves of the bifid haemal 

 spine (premaxillaries) are partly connate, and become 

 completely confluent. Each moiety, or premaxillary, is 

 reduced to the size required for the lodgement of two ver- 

 tical incisors: as the canines in man do not exceed the 

 adjoining teeth in length, and the premolars are reduced 

 to two in number, the alveolar extent of the maxillary is 

 short, and the whole upper jaw is very slightly promi- 

 nent. 



Of the diverging appendages of the maxillary arch, the 

 more constant one, called " pterji^goid," articulates with 

 the palatine, but coalesces with the sphenoid ; the second 

 pair, formed by the malar, 26, and squamosal, 27, has been 

 subject to a greater degree of modification; it still per- 

 forms the function assigned to it in lizards and birds, 

 where it has its typical ray-like figure, of connecting the 

 maxillary with the tympanic ; but the second division of 

 the appendage (squamosal) which began to expand in the 

 lower mammalia, and to strengthen, without actually 

 forming part, of the walls of the brain-case, now attains 

 its maximum of development, and forms an integral con- 

 stituent of the cranial parietes, filling up a large cavity 

 between the neural arches of the occipital and parietal 

 segments. It coalesces, moreover, with the tympanic, 

 mastoid, and petrosal, and forms, with the subsequently 



