130 ESCHRICHT AND REINHARDT 



in our two large skeletons, in this place as well as above, the limit between the diaphysis and the 

 epiphysis is, nevertheless, indicated by so deep a groove, especially in the ulna, that a cartilaginous 

 layer, penetrating very deeply, must certainly, in this place, have been inserted between 

 them. 



Tour carpal bones are most commonly in contact with the distal end of the forearm, one 

 with, the radius, one with this as well as with the ulna, and two with the latter alone. But these 

 two last-mentioned carpal bones are not in contact with each other, as the metacarpal bone of the 

 fifth finger is wedged in between them, and joined directly with the ulna, so that the latter has 

 four articular surfaces on its distal extremity. 



Besides the four bones in the first row, the carpus has only one more, which in an upward 

 direction is in contact with the three first mentioned of the carpal bones, but in a downward 

 direction with the thumb, though only in a very small part of its extent, and also with 

 the index and the middle finger. The radial bone of the carpus is contiguous only with 

 the thumb ; the third bone in the superior row, with both the fourth and the fifth finger, 

 and the ulnar bone only Avith the fifth finger. The last-mentioned carpal bone has the form 

 of a freely projecting hook, and by its relation to the carpus and the forearm, seems 

 rather to be part of the latter than of the former. It certainly projects freely from the distal 

 extremity of the ulna, just as the olecranon does from the superior one. But before we enter 

 on an interpretation of this part, as well as of the remaining bones that undoubtedly must be 

 called carpal, it will be necessary to look at these bones as they are, not only in several 

 difiereut individuals of the present species, especially at an earlier age, but also in other 

 whalebone-whales. 



Our first statement must be, then, that the only thing in which the carpal bones of all the 

 specimens of the Greenland whale examined by us agree with one another consists in the existence of 

 (1) the bone, which superiorly is contiguous with the radius as well as with the ulna ; (2) the one 

 that supports the index and the middle finger ; and (3) the one that supports the fourth and fifth 

 finger. And nevertheless we find, even in these bones, not only several differences, easy to 

 be recognised in the proportions of their dimensions, but in one case, i.e. in the left manus 

 of our eight and a half feet long foetus, we found the not unimportant deviation that 

 the bones mentioned under Nos. 1 and 3 are not totally separated from each other. This 

 peculiarity, having only been found in an immature foetus, must make us suppose that the carpus, 

 still perfectly cartilaginous, only gradually becomes divided into its single bones, and the differ- 

 ence in the proportions of their dimensions proves that the division is not always accomplished in 

 the same manner. 



Still more important, however, are those deviations which we have observed, both in the 

 carpal bone that is placed towards the radial side and in the one that is situated towards the 

 ulnar side, as to their relations to the adjoining bones. 



We have aheady, in the first section of om- memoir, found one character of the Greenland 

 whale in opposition to the Cape whale, in its thumb only consisting of one single bone, whereas in 

 the Cape whale (and the South whales in general) it consists of three, i. e. the metacarpal bone and 

 two phalanges. But according to om- observations on foetuses and newborn individuals of the 

 Greenland whale, it may be doubtful whether it can be said to have a thumb at all, as long as 

 its carpus is still quite cartilaginous. So much is certain that, in our immature as well as 

 in a full-grown foetus and in the newborn individual, we did not see, nor can we still discover, 



