260 WHALES AND DOLPHINS 



found in the upper jaw. The whole of the inner surface of 

 the mouth and the inconspicuous tongue are of a pearly-white 

 colour. 



The Sperm Whale does not have a dorsal fin, but in its place 

 a series of low ridges occupy the posterior third of the dorsal 

 surface of the body, the front and most conspicuous of these 

 being known to the old sperm whalers as the " hump ". The 

 tail flukes are from 12 to 15 feet in width from tip to tip ; 

 and the flippers, broad and rounded, are comparatively small 

 for the bulk of the animal. The eye is situated slightly 

 above and behind the angle of the gape, and the small 

 inconspicuous external opening of the ear is a little further 

 back in the region between the eye and the insertion of the 

 flipper. 



The surface of the skin is smooth and without the well-defined 

 folds seen in the Rorquals, but occasionally short ill-defined 

 wrinkles or furrows are to be found in the throat region, and 

 in very old animals the whole of the body may be covered 

 with irregular corrugations. 



The general body colour is very dark, nearly or quite black 

 on the top of the head, back and flukes, and getting lighter on 

 the sides, till on the ventral surface the colour is silvery grey 

 or white. Considerable individual variation exists, however, 

 and according to Beale in his book on ' Natural History of the 

 Sperm Whale ', published in 1839, some of the animals may 

 even be piebald. He says, too, that " old bulls . . . have 

 generally a portion of grey on the nose immediately above the 

 fore part of the upper jaw and they are then said to be ' grey- 

 headed ' ". The true body colour is often modified, especially 

 in the head region, by long white streaks and by circles — 

 abundant evidence of the whale's struggles with the giant 

 cuttlefish on which it preys for food. 



Bull Sperm Whales of very great size have been reported, 

 especially by some of the earlier whalers. Thus, F. D. Bennett 

 in his ' Narrative of a Whaling Voyage round the Globe ", 

 published in 1840, states that the greatest reported length of 

 a male is 76 feet ; and Beale, in the book already mentioned, 

 talks of : ' a full-grown male of the largest size, or about 84 feet 

 in length ". More recent measurements tend to show that 

 the male Sperm Whale never grows much longer than 60 feet. 



