154 ZOOLOGY. 



(Physeter catodon,) cylindrical cachalot, (Physalus cy- 

 lindricus,) sharp-nosed cachalot, (Physeter microps,) 

 and high-finned cachalot, (Physeter tursio y ) none but 

 the last, (which is said to be an inhabitant of the North 

 Seas, having a tall dorsal fin, and attaining the length 

 of 100 feet,) differ, in the descriptions given of them by 

 authors, from the ordinary Sperm Whale of the South 

 Seas; their specific distinctions having, apparently, 

 been drawn from peculiarities, which are commonly 

 observed to attend upon age or sex in the latter 

 species, and which I shall have occasion to notice more 

 particularly. 



In size, the Sperm Whale equals, and occasionally 

 surpasses the Greenland Whale, (Balcena mysticetus,) 

 with which it is most open to comparison. The ex- 

 perience of Captain Scoresby does not enable him to 

 assign to the Greenland Whale a greater magnitude 

 than sixty feet in length, and forty in circumference ; 

 nor have we any evidence that this species ever ex- 

 ceeds the length of seventy feet. The largest size 

 authentically recorded of the Sperm Whale is seventy- 

 six feet in length, by thirty-eight in girth ; but whalers 

 are well contented to consider sixty feet the average 

 length of the largest examples they commonly obtain.* 

 A mature foetal Cachalot, which I examined, was four- 

 teen feet in length by six in girth, which must be 



* It has been asserted, that cetacea were formerly of much greater 

 magnitude than at present ; that their being now more frequently de- 

 stroyed, precludes the possibility of their reaching a full growth. This 

 opinion is probably fallacious; or suggested by the exaggerations in 

 natural history with which the ancients have so liberally supplied us. 

 The Sperm Whale, when much inferior to its maximum size, often bears 

 an appearance of great age. The largest cetacean, with which modern 

 naturalists are acquainted, is the Razor-back Whale, (Rorqualis Jiorealis, 

 Cuv.,) which acquires the length of 100 or 110 feet. 



