ON THE GREENLAND RIGHT-WHALE. 137 



whalebone-whales to be more removed, from the common type of a mammiferous animal, and 

 accordingly the former to stand higher, the latter lower, in the systematic order of succession. 

 This supposition is, of course, principally founded on the mouth being differently armed in the 

 two groups, and in this respect the whalebone-whales must, no doubt, be said to be far removed 

 from the common organisation of a mammiferous animal, and it may further appear to be 

 confirmed by some deviations from the common structure of mammalia, which occur together 

 with the formation of whalebone, as, for instance, that the sternum only serves for the attachment 

 for a single pair of ribs, and perhaps also that the sternal ribs, if they exist at all, are 

 quite rudimentary. But it must not be forgotten that the opposite is the case in other 

 and more essential respects; thus, especially, the brain of the whalebone-whales appears 

 not a little superior to that of the toothed-whales, by the distinct development of the olfactory 

 nerves ; and it must further be considered as a proof of a higher organization that the two 

 divisions of the digestive canal, the small intestine and the colon, are distinctly separated from 

 each other, contrary to what is the case in the toothed- whales. Finally, as far as the osteology is 

 concerned, we cannot agree in the common opinion that the cranium of the whalebone-whales is 

 further removed than that of the toothed- whales from those of the rest of the mammalia; 

 according to our opinion, exactly the reverse is the case. We may, perhaps, in the first place, 

 seek some support for the correctness of our view in the fact that we do not find in the 

 whalebone-whales that want of symmetry, or distortion of the head from the right to the left, 

 which is so characteristic of the toothed-whales, and which (as it appears among these) is 

 something perfectly unknown in the rest of the mammiferous class. But our opinion may also 

 further be strengthened when we consider the form and relative position of the individual bones, 

 notwithstanding the enormous superiority of the jaws, and, perhaps, we need only in this 

 respect allude to the lower jaw, the zygomatic and lachrymal bones, the last mentioned of 

 which has not even been pointed out in any toothed-whale with the exception of Delphinorliynclius 

 micropterus and Hyperoodon. As to the rest of the skeleton, we shall here but slightly 

 glance at the fact that we might also find reasons to support our opinion in the anterior 

 extremities of the whalebone-whales ; but we must lay greater stress on this circumstance, that 

 it is only in them that we find, besides the rudimentary pelvis, remains of the other parts of 

 the posterior extremities ; and this discovery, in addition to the proofs derived also from other 

 peculiarities in their organization, must surely be said to be sufficient to secure to the whalebone- 

 whales a right to be placed at the head of the cetaceans, as the most perfect of this group of 

 animals. 



IS 



