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VIII. 



Remarks on Homology and Affinity. 



(Philosophy). 



A. General Homology. 

 1. 



On Ihe scientific significance of the genus Brisioga. considered from the stand-point of the Darwinian theory. 



When we now, after having gone through the natural history of this remarkable 

 star-fish, finally review the most important features of its organisation, we shall certainly 

 be forced to acknowledge that its structure is in reality by no means so entirely anomalous 

 as its very peculiar external appearance might induce us to suppose, and as it has indeed 

 been hitherto considered; for we can now, without any hesitation whatever, assign to it its 

 systematic place in the order of the Asteriae or star-fishes, without being forced to regard 

 it as a connecting link between the Asterise and the Ophiurse. Nevertheless this star-fish 

 exhibits in its structure some highly remarkable and significant peculiarities, which can not 

 but lead us to several reflexions on the Asterides in general, and on their relation to other 

 Echinoderms; and we shall hereby come quite naturally to the important question of the 

 relation of the whole type of Echinoderms to other animal types. It is also now my opinion 

 that this remarkable star-fish opens to us on many points a clearer view of the nature of 

 the Echinoderms than we can hitherto have had. Still it is, here as everywhere, only by 

 Darwin's reformed theory of descent, that these reflexions can bring us to more general, 

 and therefore also in a scientific point of view more important conclusions. Without Dar- 

 win's theory we should only see in the Brisinga an abnormally developed star-fish, which in 

 a remarkable and inexplicable manner seems to depart from the conventional type of Echi- 

 noderms (the radiary hemispherical form) thereby, as it were, forming one of the extreme 

 points of possible modification within the limits of the type. In regarding the matter from 

 the stand point of the Darwinian, doctrine, our reflexions take quite a different direction and 



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