Not all the bones of the vertebrate skeleton are included in the archetype as constituents of the vertebrae. Thus the branchial and pharyngeal arches are accounted part of the splanchnoskeleton, as belonging to the same category as the heart bone of some ruminants, and the ossicles of the stomach in the lobster (p. 70). The ossicles of the ear in mammals are "peculiar mammalian productions in relation to the exalted functions of a special organ of sense" (p. 140, f.n.). This recognition of a possible development of new organs to meet new functions shows unmistakably the influence of Cuvier. Owen was indeed well aware of the importance of the functional aspect of living things, and he often adopted 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 distinct 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 determining 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 (_e.g._, frogs), the long bones should ossify first at their ends, 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 element