50 



ZOOLOGY. 



The common eartli-worm (Fig. 54) is cylindrical and 

 many-jointed. The small month oisens on the under side 

 of the first segment. The eartli-worm is able to climb per- 

 pendicularly up boards or the sides of buildings by minute, 





V ^ — .....A-. a 



Fia r)i5. ~Larg:e leech, natural size, a, a tooth ; e, head enlarged with the eyes, 

 ?, triradiate teeth; t' , view of the three teeth, enlarged, tiissler, del. 



short, curved l.iri.stlcs, which are deeply inserted in the mus- 

 cnlar walls of the bod3r, and arranged in two double rows 

 along each side of ilio body (Fig. 37*). In burrowing it 

 thrusts the pharynx into the end of the head, causing it to 



