304 Royal Institution. 



tomy appeared either to have tacitly abandoned, or, with Cuvier and 

 Agassiz, had directly opposed, the idea of the law of special homo- 

 logies being included in a higher and more general law of uniformity 

 of type, such as has been illustrated by the theory of the cranium 

 consisting of a series of false or anchylosed vertebrae. Profs. De 

 Blainville and Grant, however, teach the vertebral theory of the 

 skull ; the one adopting the four vertebrae of Bojanus and the gifted 

 propounder of the theory, Oken ; the other regarding the hypothesis 

 of GeofFroy St. Hilaire of the cranial vertebrae as more conformable 

 to nature. Prof. Carus of Dresden has beautifully illustrated the 

 poet Goethe's idea of the skull being composed of six vertebrae. 

 But these authors had left the objections of Cuvier and Agassiz un- 

 rebutted ; and judging from the recent works of Profs. Wagner, 

 Miiller, Stannius, Kallmann, and others of the modem German 

 school, and those of Milne Edwards, the doctrine of unity of organi- 

 zation, as illustrated by the vertebral theory of the skull, seemed to 

 be on the decline on the Continent. To account for the law of spe- 

 cial homologies on the hypothesis of the subserviency of the parts 

 so determined to similar ends in different animals — to say that the 

 same bones occur in them because they have to perform similar func- 

 tions — involve many difficulties, and are opposed by numerous phae- 

 nomena. Admitting that the multiplied points of ossification in the 

 skull of the human foetus facilitate, and were designed to facilitate, 

 child-birth, yet something more than a final purpose lies beneath the 

 fact, that all those 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 in the human embryo, without any possibility 

 of a similar final purpose being subserved thereby. Moreover, in 

 the bird, as in the human subject, the different points of ossification 

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

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

 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 cL-priori 

 assumptions and neglect of rigorous induction on the part of Geof- 

 froy St. Hilaire, had afforded Cuvier apt subjects for the terse sar- 

 casm and polished satire which he directed against the school of 

 " Unity of Organization." 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 generally; and he finally withdrew, in the 

 second edition of his ' Legons d' Anatomic Comparee,' that small de- 

 gree of countenance to the vertebral theory of the skull which he 

 had given by the admission of the three successive bony cinctures of 

 the cranial cavity in the * R^gne 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 



