138 REPORT — 1875. 



could be determined by development, and that by that study alone could they be 

 finally demonstrated. As regards the skull, the constitution of which always 

 remains the central study of the vertebrate skeleton, his writings marked the intro- 

 duction of a period of revulsion against not only the systems of serial homologies 

 previously suggested, but even against any attempt by the study of the varieties of 

 adult forms to set them right. Mr. Huxley has added materially to the previously 

 existing number of interpretations as to what elements correspond in different 

 animals, and in doing so has found it necessary to make various additions to the 

 alreadj' troubled nomenclature. Those who consider these changes correct will of 

 com-se see in them a prospect of simplicity to future students ; but to those Avho, 

 like myself, have never been able to agree with them, they are naturally a source 

 of sorrow. Among the changes referred to may be mentioned the theory of the 

 " jieriotic bones." That theory I venture to think a very imfortunate one, intro- 

 ducing a derangement of relations as wide spread as did Goodsir's theory of the 

 frontal bone. And do not think me presumptuous in saying so, seeing that this 

 theory is in antagonism with the identifications of every anatomist preceding its 

 distinguished originator, not excepting Cuvier and Owen ; nor is it easy to dis- 

 cover what evidence it has to support it ngainst the previouisly received decision 

 of Cuvier as to the external occipital and inastoid of fishes. A^'ithout entering into 

 tlie full evidence of the subject; it may be stated that, so far as this theory affects 

 the alisphenoid in the skull of the fish, it must be given up, and the determination of 

 Professor Owen must be reverted to, when it is considered that in the carp the third 

 and fourth nerves pierce what that anatomist terms the orhitosphenoid, the bone which 

 is alisphenoid according to the theory which terms the alisphenoid of Owen the 

 prootic. A proof still more striking is furnished by Malaptertirus and other Silurids, 

 in which the bone in question is pierced by the optic nerve. That being the case, 

 the prootic theorj' will be seen to have arisen partly from giving too much impor- 

 tance to centres of ossification, and partly from considering the nerve-passage iu 

 front of the main bar of the alisphenoid of Owen as corresponding with t\\Q fora7nen 

 ovale of man rather than with the foramen rotimdam and sphenoidal fissure. A 

 spiculum, however, separatino;' the second from the third division of the fifth nerve, 

 and having therefore the precise relations of the mammalian alisphenoid, does exist 

 in the carp and other fishes. But in reptiles Professor Huxley's determination of 

 the alisphenoid is right, and Professor Owen's clearly wrong ; for in the crocodile 

 the alisphenoid of Huxley and others is perforated by the sixth nerve, so that it 

 cannot liave any claim to be called orbitosphenoid. I must, however, maintain against 

 Prof. Huxley's view Prof. Owen's determination of the nasal in fishes, notwith- 

 standing that Prof. Owen has failed to appreciate the exact relation of that bone 

 to the nasals of mammals, and has thereby laid his position open to attack. The 

 arguments on that point Prof Huxley was good enough to lay before the public 

 fourteen years ago, by kindly reading for me before the Royal Society a paper 

 which subsequently appeared in its 'Transactions;' and I am not aware that any 

 one has since attempted to controvert them. 



I shall not trouble you further with such matters of detail ; but it will be clear 

 from wliat has been said that the beginner in comparative anatomy must at 

 the present day find himself at the outset, in the most important part of his osteo- 

 logical studies, faced with a diversity of opinion and confusion of nomenclature 

 sufficient to produce much difficulty and to have a repelling effect on many minds. 

 Such difficulties might well be encoimtered with enthusiasm wliere a belief existed 

 that behind them lay a scheme of order and beauty; but not many will spend time 

 investigating such intricate details if they doubt the interest of the general con- 

 clusions likely to be reached by mastering them. On this accoimt it is a gi-eat pity 

 that the scepticism generated partly by the difficulties of the subject, and partly by 

 reaction from the dogmatism of the admirers of Oken, does too frequently dis- 

 courage the investigation of the serial homologies of the parts entering into the 

 segments of the skull, and the detei-mination of the nature and number of those 

 segments. It is a pity that so much clamour has been made for a number of years 

 against the expression " vertebral theory of the skull," because fighting against 

 words is but stupid warfare at the best, and because all that was really meant, and 

 that could be justly stated, could have been brought into prominence without ob- 



