16 The Under-Water World 



retiring habits and great powers of 

 endurance. Thanks to their " lungs " 

 the African and American species are 

 able to survive, buried during the dry 

 season in a cocoon formed in the sun- 

 baked mud at the bottom of a dried-up 

 stream-bed, when all other fish have 

 been stranded and succumbed to a 

 variety of unpleasant deaths. Lung- 

 fishes have been sent to the Zoo 

 Aquarium, walled up in lumps of clay, 

 and been admitted to a watery freedom 

 with a hammer and chisel. 



Life, as we have seen, originated in 

 the waters and assumed an infinite 

 diversity of forms as time progressed. 

 The waters were inhabited for millions 

 of years before some adventurous crea- 

 ture found that a living could be made 

 on comparatively solid ground. 



