ON THE GREENLAND RIGHT-WHALE. 131 



any traces of division between the carpal bone situated nearest to the radial side and the 

 thumb. 



Having become acquainted with these peculiarities in the radial side of the carpus, we shall 

 be better able to judge of those in the ulnar side, which are still more extraordinary. 



In the forty-four and a half feet long skeleton (see the woodcut, p. 129) the fifth finger is in 

 immediate contact with the ulna ; and here, accordingly, we have a similar case to the one existing 

 between the thumb and the radius during their less developed condition ; but the ulnar bone of 

 the carpus is distinct from the fiBger as well as from the ulna. Exactly the same peculiarities 

 are placed before us in the cartilaginous carpi of the newborn individual, and those of an almost 

 full-grown foetus, as well as in one carpus of the foetus only eight and a half feet long; 

 but in the other carpus of this same foetus this hook-like carpal bone is not yet completely sepa- 

 rated, either from the finger or from the cartilaginous extremity of the ulna. We are accord- 

 ingly led to the supposition that not only the carpus and the digits, but also the bones of the 

 forearm, have all in the beginning been formed of one single, continuous cartilage ; and at all 

 events it will be clear that in this region of the skeleton of the Greenland whale we cannot expect 

 to find any fixed or quite immutable relations between the individual bones. 



A similar uncertainty will, no doubt, be found to take place in the rorquals, as to the 

 division of this region into the single bones. By earlier researches one of us has already found 

 out^ that that hook-like carpal bone in two foetuses of the lesser fin-whale {Balænoj^tera rostratd) 

 was immediately continuous with the fifth finger, whereas in a foetus of the Greenland hump-back 

 {Megaptera longimcma) it formed a separate bone. 



Detached specimens of the carpal bones of the Greenland whale, with their recent cartilaginous 

 surfaces, are scarcely ever placed before the zoologist for his examination. But this may very 

 well happen with their bony nuclei ; and we shall not, therefore, in this place, omit to mention 

 the very peculiar appearance these present after they have been deprived of their surrounding 

 cartilaginous layer. 



The ossification of the carpal bones, as that of short and thick bones in general, begins from 

 a single nucleus in the middle, and reaches the free surfaces only very slowly. In those of the 

 newborn individual no traces of ossification were as yet found ; and even in the forty-four and a 

 half feet long skeleton, which we have pointed out as full-grown, the single carpal bone in the 

 second row was still quite cartilaginous at both its free surfaces, so that it was not till it had 

 been cut through that an osseous nucleus, very small comparatively speaking, appeared in its 

 interior. 



As long as the osseous nucleus of any such cai-pal bone is still buried in its interior its form 

 has not the most distant resemblance to that of the whole bone ; it seems, even for a long time, 

 to remain perfectly globular in all of them. Afterwards it grows faster towards the two 

 surfaces, and as soon as it has reached these it spreads gradually on them, becoming flattened 

 at the extremities. Thus, these bones very frequently acquire the shape of a barrel, 

 often showing, at the same time, a contraction between the ends and the middle part, which 

 still retains in some degree its original globular form. It is not till very late that the osseous 

 nucleus spreads chiefly on the two free surfaces of the bone, and then the whole ossification 

 often becomes very irregular. 



^ See the ' Transactions ' of this Society, 3rd series, vol. xi ; Eschricht, ' Undersogelser cm Hval- 

 dyrene ' (Researches upon the Cetaceans), 3nd essay, plates ii and iii. 



