44 PRACTICAL ZOOLOGY, 



kind, in which the sexes are united in the same 

 individual, are called hermaphrodites. 



17. There are no lungs, no gills. Oxygen is taken by the 

 blood as it circulates, through the skin. 



18. There are no eyes, but the first two segments seem to 

 be sensitive to light. 



19. The worm, in digging a new hole, or deepening an old 

 one, swallows the soil, and passes it through its 

 intestine, the partly decayed vegetable matter in the 

 soil furnishing nourishment to the worm. The coiled 

 castings at the tops of the holes have probably been 

 noticed by all. In damp weather the worms come to 

 the surface to draw leaves, twigs, and seedling plants 

 into their holes. These holes are sometimes six feet 

 deep. It is found that the leaf is rolled together and 

 drawn into the hole with the stem pointing up. 

 Taken an inch or two below the surface, the leaves 

 soon become softened, and in a partly decayed condi- 

 tion are eaten. In this way, without the aid of teeth 

 or hard jaws, the worm obtains food solely by the 

 suctorial power of its proboscis. 



20. Make a drawing showing the whole digestive canal as 

 seen from above. Draw a cross-section of the body 

 (i.e., what is seen if the body is cut across), and a 

 vertical longitudinal median section (as seen by 

 splitting lengthwise, from top to bottom, in the middle 

 line). 



RANK OF EARTHWORMS AMONG ANIMALS. 



Animals are ranked according to the number of things 

 they can do, and do well. The earthworm has many 

 parts, but they are all nearly alike, and do not enable it to 



