220 GENERAL AND SPECIAL TERMS IN OSTEOLOGY. 



ancliylosed stylobyal, a compound bone called " temporal" 

 in human anatomy. The key to the complex beginning 

 of this "cranial" bone is again given by the discovery of 

 the general pattern on which the skulls of the vertebrate 

 animals have been constructed. In relation to that pat- 

 tern, or to the archetype vertebrate skeleton, the human 

 temporal bone inclndes two pleurapophyses, 38 and 28, a 

 parapophysis, 8, part of a diverging appendage, 27, and a 

 sense-capsule, 16. 



The departure from the archetype, which we observe 

 in the human skull, is most conspicuous in the neural 

 spines of the three chief segments, which, archety pally, 

 may be regarded as deformities by excess of growth to 

 fulfil a particular use, dependent on the maximization of 

 the brain ; the deviation is again marked by arrest of 

 growth or suppression of parts, as e. g. in certain parapo- 

 physes, and in the haemal arch of the parietal segment ; it 

 is most frequently exemplified in the coalescence of parts 

 primarily and archetypally distinct; and it is finally mani- 

 fested by the dislocation of a part, viz : the haemal arch 

 of the occipital segment — the diverging rays of which 

 have become the seat of that marvellous development 

 which has resulted in the formation of the osseous basis 

 of the human hand and arm. With the above explana- 

 tion the structure of the human skull can be intelligibly 

 comprehended, and not merely empirically understood, 

 as through the absolute descriptions penned in reference 

 to material and utilitarian requirements, and without re- 

 ference to the great scale of vertebrate structures, of which 

 man is the summit. 



The fruit of a series of comparisons, extended over all 

 the vertebrate kingdom, being the recognition of the 

 archetype governing the structure of the vertebrate skele- 



