110 TRANSCENDENTAL ANATOMY IN' ENGLAND 



the teleological point of view. As a true morphologist, 

 however, he held that the principle of adaptation does not 

 suffice to explain the existence of special homologies. The 

 ossification of the bones of the skull from separate centres 

 may be purposive in Eutheria, in that it prevents injury to 

 the skull at birth ; but how explain on teleological principles 

 the similar ossification from separate centres in marsupials, 

 birds and reptiles ? How explain above all the fact that the 

 centres are the same in number and relative position in all 

 these groups ? Surely we must accept the idea of an 

 archetype " on which it has pleased the divine Architect to 

 build up certain of his diversified living works" (p. 73). 



In his study of centres of ossification, Owen made in 

 point of theory a distfnct advance on his predecessors. 

 We saw that Geoffroy recognised the importance of 

 studying the ossification of the skeleton, and that Cuvier 

 accepted such embryological evidence as an aid in deter- 

 mining homologies. Owen pointed out that it was necessary 

 to distinguish between centres of ossification which were 

 teleological in import and such as were purely indicative of 

 homological relationships. Many bones, single in the adult, 

 arise from separate centres of ossification, but we must 

 distinguish between " those centres of ossification that have 

 homological relations, and those that have only teleological 

 ones ; i.e., between the separate points of ossification of 

 a human bone which typify vertebral elements, often 

 permanently distinct bones in the lower animals ; and the 

 separate points which, without such signification, facilitate the 

 progress of osteogeny, and have for their obvious final cause 

 the well-being of the growing animal" (p. 105). There is, 

 for example, a teleological reason why in mammals and leaping 

 Amphibia (<\{, r ., frogs), the long bones should ossify first at their 

 (.nds, for the brain is thus protected from concussion ; in 

 reptiles that creep there is less danger of concussion, and 

 the long bones ossify in the middle (p. 105). But there is 

 no teleological reason why the coracoid process of the scapula 

 should in all mammals develop from a separate centre. The 

 coracoid is however a real vertebral clement (haemapophysis), 

 and in monotremcs, birds and reptiles it is in the adult a 

 large and separate bom-. Its ossification from a separate 



