ON THE GREENLAND RIGHT-WHALE. 81 



they pass beneath the occiput, are curved inwards, so as to become sUghtly sigmoid, and are 

 articulated very inwardly with the lateral parts of the temporal bones.^ 



Passing now to a more particular description of the osteology of the head of the Greenland 

 whale, we shall principally be guided by, or at least begin with, the forty-seven feet and a half 

 long skeleton, to the illustration of which in the first figure of the second plate we have already 

 directed the attention of our readers. In this figure, the skull is seen from the side, in the 

 second figure of the same plate, it is seen from behind (20 times diminished), in the fourth plate, 

 the posterior part of it is shown from above and from below. 



As the most characteristic feature in the skeleton of the Greenland whale is the extraordinary 

 size of the head, so the most characteristic feature of its head is the disproportionate size of 

 the jaws relatively to the cranium, properly so called, or rather the disproportionate size of the 

 cavity of the mouth compared with that of the cranium. But while the former characteristic 

 disproportion in the skeleton, considered as a whole, may be said to be prevalent in every 

 period of age, as the head already in the newborn individual as well as in the foetus, occupies 

 a third of the entire length of the body, the disproportionate size of the jaws, or the cavity of 

 the mouth, only gradually developes itself during the growth of the animal. 



This is evidently in perfect conformity with the fact that the brain on the one hand is 

 one of those organs which first appears in the animal, and has already attained to the full size in 

 the half-grown whale, while, on the other hand, the whalebone does not appear until at the 

 beginning of the latter half of uterine life, being still only four inches long in the newborn animal, 

 and in the half-grown one a little more than three feet ; it has accordingly only attained 

 one fourth of its full size at a time when the brain has already ceased to grow, and, as in all 

 animals, the grovi'ih of the skull, properly so called, must necessarily correspond to that of the 

 brain, so in the whalebone whales the growth of the jaws must conform with that of the whale- 

 bone. It is true, that the proportion is in the latter respect not quite the same ; for in the small 

 foetus of a Greenland whale, still unprovided with whalebone, the jaws already occupy a greater 

 part of the head than the cranium ; but this is only the consequence of the general rule that in 

 the development of every organ, its future importance is indicated beforehand. That in other 

 respects the development of the jaws correspond to that of the whalebone, cannot be doubted, 

 for every one of theii* peculiarities as well as all the specialities in the structure of the entire 

 head, can only find their proper explanation in the exceedingly great development of the 

 whalebone. 



Thus, in particular, the arched form of the palate is necessitated by the rapidly increasing 

 length of the whalebone from the two extremities towards the middle of the palate, while the 

 comparatively small breadth of the whalebone produces a corresponding narrowness of the sides 

 of the palate, and of the upper jaw generally ; but the great number of the whalebone-blades 

 necessitates at the same time an extraordinary length of both the jaws, and the great distance of 

 the lower extremities of the two rows of laminæ from each other necessitates a corresponding 

 curve of the two lateral branches of the lower jaw in an outward direction. The immense weight 



^ The greater part of these peculiarities of the jaws of the rorquals may be seen in our third 

 plate, figs. 2 and 3. Fig. 2 represents the skull of a forty-three feet long specimen of a hump-back. 

 Fig. 3 the skull of a fifty-three feet and two-thirds long skeleton of a fin-whale, both from Greenland, 

 and both exhibited in the zootomical-physiological Museum. 



11 



