SPERM-WHALE. Ill 



covering of blubber which everywhere envelops the body produces 

 the valuable sperm-oil of commerce ; hence this animal has long 

 been the subject of a regular chase, by which its numbers have been 

 greatly diminished. The substance called " ambergris," largely 

 used in perfumery, is a concretion formed in the intestines of the 

 Sperm -Whale, and is found floating on the surface of the seas 

 which they inhabit. Its genuineness is attested by the presence of 

 fragments of the horny beaks of the cephalopods on which the 

 Whales feed. 



A large skull of a Sperm- Whale, which has been in the Museum 

 since the end of the last century, is placed in the anteroom through 

 which the Cetacean Gallery is entered, and the remarkable form 

 of the lower jaw, with its numerous stout conical teeth, is shown 

 in a specimen suspended to the ceiling near the entrance of the 

 Gallery. 



Nearly allied to the Sperm- Whale, but of very much smaller 

 size, is Kogia breviceps, of which but few specimens have hitherto 

 been met with. The skeleton exhibited is from the neighbour- 

 hood of Sydney. 



The Ziphioid Whales, or Ziphiinffi, a section of the Physeteridae, 

 constitute a very interesting group, of which most of the different 

 forms are represented in the collection by skeletons and skulls. 

 They resemble the Sperm-Whale and Kogia in having no teeth in 

 the upper jaw (or if present they are in an exceedingly rudimen- 

 tary state, and attached only to the gum of the mouth, not fixed 

 in the bone), but differ, inasmuch as in the lower jaw the teeth, 

 instead of being numerous, are reduced to one, or very rarely two, 

 pairs. These are situated either quite at the front extremity of the 

 jaw, as in Ziphius and Hyperoodon, or near the middle, as in Me- 

 soplodon. In one of the last-named genus (M. layardi], from the 

 South Seas, these teeth are much elongated and flattened, and in 

 old animals (as in the skull exhibited in the Table-Case) curve 

 round and meet over the upper jaw, so as almost to prevent the 

 mouth from opening. This remarkable disposition of the teeth has 

 been found in so many individuals that it must be looked upon as 

 normal, and not, as at first thought, an accidental peculiarity, 

 though it is difficult to understand how it is consistent with the 

 animal obtaining its food. 



The best known animal of this group found in the British seas 



