126 Scientific Intelligence. 



points of ossification in the skull of the human fcetus facilitate, and 

 were designed to facilitate, child-birth, yet something more than a final 

 purpose lies beneath the fact, that all these points represent permanently 

 distinct bones in the cold-blooded vertebrata. And again, the cranium 

 of the bird, which is composed in the adult of a single bone, is ossified 

 from the same number of points as the human embryo, without any 

 possibility of a similar final purpose being subserved thereby. More- 

 over, in ihe bird, as in the human subject, the different points of ossi- 

 fication have the same relative position and plan of arrangement as in 

 the skull of the young crocodile; in which animal they always, main- 

 tain, as in most fishes, their primitive distinctness. A few errors, some 

 exaggerated transcendentalisms and metaphorical expressions of the 

 earlier German homologists, and a too obvious tendency to d-priori 

 assumptions and neglect of rigorous induction on the part of Geoffroy 

 St. Hilaire, had afforded Cuvier apt subjects for the terse sarcasm and 

 polished satire which he directed against the school of " Unitv of Or- 

 ganization." The tone also which the discussions gradually assumed 

 towards the latter period of the career of the two celebrated anatomists 

 of the French Academy, seems to have led to a prejudice in the mind 

 of Cuvier against the entire theory and transcendental views gene- 

 rally ; and he finally withdrew, in the second edition of his * Lecons 

 d'Anatomie Comparee,' that small degree of countenance to the ver- 

 tebral theory of the skull which he had given by the admission of the 

 three successive bony cinctures of the cranial cavity in the * Regne 

 Animal.' 



Prof. Owen then briefly alluded to the researches which he had 

 undertaken, with a view to obtain conviction as to the existence or 

 otherwise of one determinate plan or type of the skeletons of the ver- 

 tebrata generally; and stated, that after many years' consideration 

 given to the subject, he had convinced himself of the accuracy of the 

 idea that the endo-skeleton of all vertebrate animals was arranged in a 

 series of segments, succeeding each other in the direction of the axis 

 of the body. For these segments or " osteocommata" of the endo- 

 skeleton, he thought the term kt vertebrae' 1 might well be retained, al- 

 though used in a somewhat wider sense than it is understood by a hu- 

 man anatomist. The parts of a typical vertebra were then defied, 

 according to the views explained in the Professor's fc Lectures on Ver- 

 tebrata ;' and he proceeded to apply its characters to the four segments 

 into which the cranial bones were naturally resolvable. The views o 

 the lecturer were illustrated by diagrams of the disarticulated skulls ot 

 a fish, a bird, a marsupial quadruped, and the human foetus. 1 he 

 common type was most closely adhered to in the fish, as belonging 10 

 that lower class of vertebrata in which " vegetative repetition"* M° si 

 prevailed, and the type was least obscured by modifications and combi- 

 nations of parts for mutual subservience to special functions. The 

 bones of the skull were arranged into four segments or vertebra?, an- 

 swering to the four primary divisions of the brain, and to the nerve* 



# r 



The general principle of animal organizations, which Prof. Owen has term? 



Jtuion, 55 is explained in the first volume o 



the law of vegetative or irrelative repetition," is explained 

 his • Hunterian Lectures, — on the Invertebrate Animals.' 



