Anatomical Structure of certain of the Cetacea. 407 



the capacity of the pelvic apertures, maybe readily judged of 

 by reflecting on the elongated square form of the pelvis of the 

 seal ; but it is equally obvious, that the artificial separation of 

 the bones of the human pelvis, by a section of the ligamentous 

 symphysis, cannot produce the same results, by reason of the cir- 

 cular form of the cavity of the human pelvis. The pretended 

 reasoning from analogy, then, on the part of those who have 

 proposed imitating a process of nature, in dividing the human 

 symphysis pubis during laborious or difficult parturition in wo- 

 men, argues merely a want of accurate observation on their 

 part, and is an attempt to supply one animal with a mechanism, 

 which Nature exclusively intended for another, whose structure 

 was originally entirely different*. 



The total length of the skeleton of the narwal, apparently 

 that of an adult animal, in the Barclayan Museum, as now arti- 

 culated, and which is said to have been presented to Dr BAR- 

 CLAY by Captain SCORESBY, is 16 feet 3 inches. Length of the 

 head 2 feet ; of the tusk 6 feet 1^ inches, being that remarkable 

 single tooth which has in all ages characterized this animal ; it 

 being also well known that, in the male, the left tusk only is 

 developed so as to protrude beyond the gums, whilst the right 

 remains imbedded in the jaw for life ; in the female both tusks 

 remain in this latter state ; the part imbedded within the socket 



* In an Essay on the History of Whales, by the Honourable P. DUDLEY, Phil. 

 Trans. 1725, the following observations occur as to the bulk of the foetus of the 

 Whale. 



" WHALEBONE WHALE. This fish, when first brought forth, is about 20 feet 

 long, and of little value : the full-grown animal is 60 or 70 ; say as 1 to 3. 



" SPERMACETI WHALE. The calf, or young whale, has been found perfectly 

 formed in the cow when not above 17 inches long, and white; yet, when brought 

 forth, it is usually 20 feet, and of a black colour." 



