OCR Text |
Show 1879.] 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 dislocations. 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 laceration 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:- |