152 ANARTHROPODA 



through to the superficial blood vessels and in an hour the 

 hungry creature will be distended to triple its former size. 

 The alimentary canal has several pouches along either side 

 to increase its capacity. A full meal lasts the animal one 

 year. 



Tn some parts of the tropics such as India and Ceylon, 

 there are land leeches about an inch long in the meadows 

 and woods capable of scenting their prey at some distance, 



FIG. 179. Night walker ; c, clitellum ; TO, mouth ; n, opening of reproductive glands. 

 Photograph natural size. 



and are quick in their movements, so that a person brushing 

 through the jungle often becomes covered with them. The 

 largest leech is an American species, Macrobdella valdiviana, 

 which attains a length of more than two feet. 



Earthworms. These are often called rain worms or 

 angleworms. There are a dozen or more species in tliis 

 country, but for study the night walker (Lumbricus agri- 

 cola) is best on account of its large size. It may be recog- 

 nized by its flattened posterior end. It lives in rich garden 

 soil and near manure piles. In dry weather the holes may 

 extend to a depth of six feet. Specimens may often be 



