384 MORE ABOUT WHALES 



It has been suggested that these networks of blood- 

 vessels are related in some way both to the power of 

 keeping long (forty minutes !) under water without 

 breathing, and also to the freedom of these marine 

 monsters from the deadly effects of rapid passage from 

 great to little gas-pressure. But it is only a suggestion ; 

 no one has shown how the networks can act so as to 

 effect these results, and I am quite unable to'say how they 

 can do so. Another suggestion worth considering is that 

 the whale completely empties the gas out of its lungs by 

 muscular compression of the body-wall before diving, so 

 that there is no gas left in the body to be acted on by the 

 increased pressure resulting from its sinking into deep 

 water. I am unable to deal with this puzzle myself, and 

 I have not been able to find any naturalist or physiologist 

 who can throw light on the matter. 



The toothed whales are nearer to the ancestral primi- 

 tive whales than are the whalebone whales. The latter 

 are the more peculiar, and specially adapted with their 

 huge heads and mouths (a third the length of the 

 whole animal in the Greenland whale), and their pali- 

 sades of 350 whalebone planks, some 12 ft. long, on 

 each side of the mouth. I may mention in parenthesis 

 that, whilst whalebone has been largely superseded by 

 light steel in the making of umbrellas and corsets, its 

 value remains, or rather increases, on account of its being 

 the only material for making certain kinds of large 

 brushes which are used in cleaning machinery. The 

 whalebone whales have, when first born, very minute 

 teeth hidden in their jaws ; they disappear. Some of 

 the toothed whales have teeth only in the lower jaw 

 (the cachalot), others (the beaked whales, Ziphius, etc.) 

 have only one pair or two pairs of teeth. These are 

 tusk-like, and placed in the lower jaw. Others (the 

 dolphins and porpoises) have very numeroi;s peg-like 



