18/9.] PROF. FLOWER ON THE SKULL OF A BELUGA. 669 



any previous disease in this or any other part of the vertebral 

 column. The formation of new bone, resulting in ankylosis, is what 

 might naturally be expected to occur as the consequence of such an 

 injury, and is the usual sequence of dislocation of the atlas, when 

 not immediately fatal, in the human subject. 



In the present case it is difficult to imagine how such an accident 

 can have been occasioned, as in the case of an aquatic animal there 

 is no possibility of a fall on the head, the common cause of such dis- 

 locations. Even a violent collision of the head against a rock or 

 ship can scarcely have produced such displacement, in the case of 

 an animal floating freely in the water, unless there were some 

 counterpressure causing resistance on the part of the trunk. The 

 animal certainly had received a blow on the fore part of the head, 

 as at about three inches from the apex of the rostrum, on the right 

 side, there is a roughened surface on which new bone has been 

 thrown out, very probably at the same date as that at the occiput, 

 and long antecedent to the recent wound observed at the time of its 

 capture. 



However the injury may have been brought about, the specimen 

 affords a remarkable illustration of recuperative power, as the lacera- 

 tion of all the parts around the articulation, and effusion of blood from 

 the plexus surrounding the cord, must have been considerable, and 

 the ability to pursue and capture living prey must have been, for a 

 time at least, greatly interfered with. The spinal cord itself being 

 of comparatively small diameter in proportion to the size of the 

 aperture through which it passes, seems to have escaped serious 

 injury, and to have accommodated itself to the abnormal position of 

 the surrounding bones. After recovery the head was fixed in a very 

 abnormal position with regard to the body, which may account for 

 the wandering of the animal so far from its natural habitat, and for 

 the facility of its capture. 



The following papers were read : — ■ 



