226 THE HAUNTS OF LIFE 



HAUNTS WITHIN HAUNTS 



Until an animal becomes big-brained and 

 resourceful, or is endowed with a rich equip- 

 ment of inborn gifts which we call instincts, 

 or has some special ways of protecting itself 

 or effacing itself, the surface of the earth is a 

 hazardous home. This makes it easy to un- 

 derstand why there should be haunts within 

 haunts, such as caves and grottos; why some 

 land animals become subterranean burrowers 

 and others arboreal climbers ; why some have 

 returned to the water, like the water-beetles 

 and the whales; and why some have sneaked 

 inside other animals. 



BENEATH THE GROUND 



Among the first animals to discover the 

 world beneath the ground were the earth- 

 worms. The strong probability is that they 

 originally belonged to a fresh-water stock, for 

 several earthworms have gills. When they 

 colonised the dry land and became able to 

 breathe dry air through their moist skin, they 

 must have had for a time a Golden Age. 

 Land vegetation had been established, and 



