DUGONGS, MANATEES, WHALES, PORPOISES, DOLPHINS 295 



but many of the fingers contain mure bones than the fingers of man. In some whales we 

 find a dorsal fin, and this, as also the flippers, acts as a balancer. In no whale or 

 porpoise is there any external trace of hind limbs, but the skeleton of some kinds shqws in 

 varying stages of degradation a rudimentary bone answering to this description. Perhaps, 



however, the most distinctive feature of whales is the blow-hole, situated, like the nostrils 

 of the hippopotamus, on the upper surface of the head, and similarly enabling the animal to 

 breathe the air without exposing much of its head above the surface of the water. The 

 blow-hole (or blow-holes, for whalebone-whales have two) may be said to take the place of 

 nostrils as regards the breathing, though perhaps no sense of smell is included in its function-. 

 In the Sperm-whale, or Cachalot, then- is a single (/j-shaped blow-hole near the end of the 

 snout. The well-known spouting of whales is merely the breathing out of warm vapour, which, 

 on coming in contact with the colder air — and it should be remembered that most whaling is 

 carried on in the neighbourhood of icebergs — condenses in a cloud above the animal's head. 

 I have seen many a sperm-whale spout, and the cloud of spray, often mixed with a varying 

 volume of water if the whale commences to blow before its blow-hole is clear of the surface, 

 drifts forward over the forehead. This is due to the forward position of the blow-hole. I never 

 to my knowledge saw a whalebone-whale spouting, but its double jet is said to ascend vertically 

 over its back, and this would in like manner be accounted for by the more posterior position 

 of the blow-holes. Having filled its lungs, which are long and of simple structure, with fresh 

 air, in enormous draughts that till the great cavities of its chest, the whale sinks to the 

 depths. There, in ordinary circumstances, it will lie for a quarter of an hour or more, but 

 the pain of the harpoon and the knowledge that there is danger at the surface may keep it 

 below for as much as an hour. When it has to breathe again, a few powerful strokes from 

 the laterally set tail suffice to bring it quickly to the surface. This is not the place for a 

 detailed anatomy of the whale, but no one can fail to notice with admiration such parts of 

 its equipment for tin- battle of life as the structure of its windpipe, which enables it to breathe 

 with comfort with its mouth full of water, the complicated network of blood-vessels that 

 ensures the slow and thorough utilising of all the oxygen in its lungs while it remains at the 

 bottom, and the elastic cushion of blubber that makes this gigantic animal indifferent to 

 extremes of pressure and temperature. Thanks mainly to its coat of blubber, the whale 

 exists with equal comfort at the surface or hundreds of fathoms below it; in the arctic or in 

 tropical seas. 



It is not perhaps in keeping with the plan of this work that we should consider in detail 

 the soft parts of the whale's inside. One or two parts of its feeding and digestive mechanism 

 may, however, offer some points of passing interest. The complex stomach, which is divided 

 into chambers, like that of the ruminants already described, has suggested that the latter function 



Photo bj A. S. RudUnd if Sons 



SHORT-BEAKED RIVER-DOLPHIN 



In this type the head is produced into a bcakj supported in the upper ..-:;.- by a mass of ivory-It ke bone 



