120 SEA SNAKE A BASKING SHARK. [CHAP. VI1L 



of the northern sea snake, agree perfectly with the idea of the 

 projecting back of a shark followed by a succession of waves, 

 diminishing in size as they recede from the dorsal prominence. 



The parts before mentioned as alone visible above water would 

 form so small a portion of the whole body, that they might easily 

 convey the notion of narrowness as compared to great length ; 

 and the assertion of a few witnesses that the dorsal projections 

 were pointed, may have arisen from their having taken a more 

 accurate look at the shape of the fins, and distinguished them 

 better from the intervening waves of the sea. But, according to 

 this view, the large eyes seen in the &quot; blunt head&quot; by several 

 observers, must have been imaginary, unless in cases where they 

 may have really been looking at a seal. It can hardly be doubted 

 that some good marksmen, both in Norway and New England, 

 who fired at the animal, sent bullets into what they took to be 

 the head, and the fact that the wound seems never to have pro 

 duced serious injury, although in one case blood flowed freely, 

 accords perfectly with the hypothesis that they were firing at the 

 dorsal prominence, and not at the head of a shark. The opinion 

 of most of the observers that the undulations were coincident with 

 the rapid movements of the creature, agrees well with our theory, 

 which refers the greater number of the projections to waves of 

 the sea. On the other hand, as several of the protuberances are 

 real, consisting of three fins and a part of the back, the emergence 

 of these parts may explain what other witnesses beheld. Dr. 

 Melville has suggested to me, that if the speed were as great as 

 stated, and the progressive movement such as he has described,*&quot; 

 the three fins would be first submerged, and then re-emerge in 

 such rapid succession, that the image of one set would be retained 

 on the retina of the eye after another set had become visible, and 

 they might be counted over and over again, and multiplied in 

 definitely. Although I think this explanation unnecessary in 

 most cases, such a confusion of the images seems very possible, 

 when we recollect that the fins would be always mingled with 

 waves of the sea, which are s-aid, in the Norwegian accounts of 

 1845, to have been so great, that they broke on the coast in 

 * Ante, p, 119. 



