222 HANDBOOK OF NATURE STUDY 



Moles and shrews burrow for them in the ground ; birds, 

 toads, salamanders, and predaceous beetles devour them 

 whenever they appear on the surface. Although earthworms 

 have no organs of hearing, they do perceive vibrations of the 

 ground, which are caused by the walking of men and animals, 

 and these vibrations cause them to retreat into their burrows. 

 They leave their burrows only at night, and then only when 

 the ground is wet, because they cannot move over dry sand 

 or dust. Can you tell why not? Towards morning they 

 return into the ground. They have no eyes, but investi- 

 gators have proved that a few of the rings near the mouth 

 are able to perceive the light. An earthworm placed in 

 bright sunlight shows by its motions that either the light 

 or the warmth, or both, are exceedingly painful to it. In 

 the morning earthworm tracks can be seen everywhere on 

 moist, bare ground, and on rainy days they can be seen in 

 the daytime creeping on stone and on wooden walks. From 

 which ones of their enemies do their nocturnal habits pro- 

 tect them ? 



The food of earthworms consists of decaying animal and 

 vegetable matter, such as is abundantly present in all rich 

 field and garden soils. Why do boys not look for earth- 

 worms in sterile, sandy soils ? The earthworm has no dis- 

 tinct head, but you will find the mouth on the anterior end 

 of the body. They often devour large masses of dirt and 

 extract their food from it, and if there is not sufficient food 

 in the soil, they will pull leaves, straws, and other objects 

 into their burrows and eat them when they begin to decay. 

 Have you seen leaves and straws "planted" by earthworms? 



We have learned that the earthworm, although it has 

 none of the sense organs of higher animals, is nevertheless 

 enabled very often to escape from its enemies. But how can 

 a being of such low organization cope with adverse conditions 



Observations. By what means are they scattered ? 



