402 VERTEBRATE ZOOLOGY 



feet. Its circumference in front of the flippers was thirty-seven feet; 

 it was twelve feet in height at the shoulders. This enormous animal 

 did not impress one as a long slender type, but as distinctly stocky, 

 retaining its great diameter from the end of the snout to within 

 about fifteen feet from the tail. The lower jaw of the sperm whale 

 is long and narrow and is armed with from forty to forty-eight conical 

 teeth that fit into the toothless groove of the upper jaw. A large 

 cavity in the skull is filled with a liquid oil, spermaceti, which is a 

 valuable product. This reservoir of light oil is believed to be largely 

 of hydrostatic value, in that it must be quite buoyant. The huge 

 skull is the most highly modified skull known for a mammal. The 

 right maxillary and left nasal bones are much larger than their fel- 

 lows, the right nasal being vestigial. The top of the skull has a great 

 bony crest running diagonally instead of mesially as in other skulls. 

 The cervical vertebrae are largely fused into a short immovable neck. 

 The sperm whale is valuable for spermaceti, for oil made from blub- 

 ber, and for ambergris; the latter is a very valuable product said to 

 be worth its weight in gold, and is a cumulative byproduct of in- 

 testinal digestion, having a composition somewhat like cholesterin. 

 Ambergris is used in imparting long-lasting quality to fine perfumes 

 and even minute quantities add value to considerable volumes of 

 perfume. The food of the sperm whale consists largely of giant 

 squids, as may be judged by the remains of the latter found in the 

 whale's stomach. 



One of the most fish-like of the toothed whales is the killer (Fig. 

 207, A), Orca, a small species that has the reputation of killing larger 

 whales. 



Beaked whales are animals of moderate size, seldom more than 

 thirty feet in length; they have a prolonged muzzle armed with 

 numerous teeth. They are quite slender and doubtless have done 

 duty as "sea serpents." Dolphins and porpoises (Fig. 207, B) are 

 small whales of rather generalized structure. They have teeth in 

 both jaws, and the head is more mammal-like than that of other 

 whales. According to Flower, there are nineteen genera of these 

 small whales, and they comprize a considerable majority of all exist- 

 ing cetaceans. They are distinctly gregarious, running in schools of 

 considerable size. Their habit of leaping out of the water at inter- 

 vals makes them an interesting sight for ocean travelers. Closely 

 allied to the porpoises is the narwhal, a form in which the teeth are 



