CHAPTER XIV 



THE EARTHWORM, NEREIS, AND THE 

 LEECH. ANNELIDA 



Almost everywhere in England earthworms are found. 

 They live usually in the upper layers of the soil 

 in burrows, which they make partly by boring 

 with the pointed front ends of their bodies, partly by 

 swallowing the earth in front and passing it out behind, in 

 which case the earth which is passed out forms the well- 

 known " worm casts." The sides of the burrow are lined 

 with a slime secreted by unicellular glands in the skin, and 

 if the opening be not protected by a worm cast it is usually 



Fig. 133. — The Earthworm. — From Thomson. 



closed by leaves or small stones. Such leaves may often be 

 seen sticking up from the ground, and will be found to 

 have been pulled into the burrow skilfully, with the 

 narrowest part foremost. At night, if the weather be warm 

 and not too dry, the worms will stretch themselves out of 

 their holes, keeping the hinder end of the body fixed in the 

 opening, so that they can pull themselves back at once if 

 danger threatens. In dry weather or hard frost they burrow 

 deep and retire to a small chamber, which they line with 

 little stones. In wet weather they are sometimes flooded 



