17 



the purpose of forming the blow-hole from which the animal 

 spouts.f 



I have before said that at the back of the head or occiput, 

 there rises a sort of semicircular wall, almost perpendicularly. 

 This is formed by the right bone of the nose, the base of the 



t There is every reason to believe that the Scotch whale, described by Sir 

 R. Sibbald, with forty-two teeth in the under jaw, was the Black fish, or 

 Physeter Tursio of Linnaeus, and it is also, perhaps, although I confess I have 

 great doubts, the species of which Beale saw the skeleton in the possession of 

 Sir Clifford Constable, in Yorkshire. Unfortunately, I am not able to 

 refer to Dr. Alderson's paper. According to Sibbald, in the Black 

 fish, a little above the middle of the rostrum, " there is a lobe which is called 

 the lune, having two entrances covered with one operculum, called the 

 Jlap^ Now, from the relation which the position of the nostrils in the skull 

 bears to that of their single external opening, or Mow-hole, at the front of the 

 snout in the genus Catodon, we may infer that a blow-hole placed nearer the 

 middle of the head, as in the Black fish, would not so much distort the 

 general appearance of the head. And here, by the way, I may observe, that 

 the words "spiracle" and "blow-hole" appear to be better names than 

 *'spouter" for that external orifice by which the canal from the nostrils 

 opens to the atmosphere ; particularly if Beale be correct, who asserts that 

 these animals never eject water from their nostrils, but only vapour. No 

 better external characteristic of the true sperm whales, or genus Catodon^ 

 has yet been given than the position of their single blow-hole at the summit 

 of their snout — the " fistula in rostro" of the old naturalists. It is as good a 

 character as theu- fat quadrangular snout itself. And were it not that the 

 Black fish, or genus Physeter, is said to have the blow -hole at the middle of 

 the snout, as another cetacean of the same family, hereafter to be described, 

 most certainly has likewise, all the CatodonUd<s, or family of sperm whales, 

 might thus be neatly separated from dolphins. The genus Catodon agrees 

 with the herbivorous Cetacea alone, in having the nostrils opening at the 

 extremity of the snout. It is not the object of the present work to enter 

 particularly upon the external appearance of sperm whales, or upon the 

 anatomy of their soft parts. Indeed, as yet, I have had few opportunities of 

 studying such subjects. I may remark, however, that nothing is certainly 

 known of the mode in which the single spiracle of the sperm whales 

 communicates with the two nostrils in the skull. John Hunter would seem 

 to assert, that there is only a single tube or canal from the commencement, for 

 both nostrils. In some dolphins, on the other hand, there is said to be a 

 dividing membranous septum. But all this subject requires further 

 investigation ; the only thing which appears certain, being, that their single 

 external spiracle proves the Catodontidce to be rather dolphins than true 

 whales, which last have two distinct external spiracles, communicating by 

 separate canals with the holes in the skidl. 



