THE EARTHWORM. 131 



Specimens for study may be obtained by digging, and 

 at night by simply picking them up when they are out 

 of their burrows and extended on the ground. At sun- 

 rise they may be seen in the mouths of their burrows, or 

 partly extended, not having retired for the day. This 

 explains why "the early bird catches the worm." 



Field Study. In the field, observe : 



1. The quickness with which they retreat when dis- 

 turbed by a heavy step on the earth near their burrow. 



2. The force with which they cling to their burrows 

 when an attempt is made to drag them forth. 



3. Their insensibility to sounds, however loud, and 

 their slow sensibility to light. 



4. The size, direction, and depth of their burrows. 



5. The plugs found stopping the mouths of the bur- 

 rows in the daytime, the materials used, and the skill 

 shown by the worms in their method of plugging. 



In winter, specimens obtained by digging may be placed 

 in a box, or large flowerpot, of earth, and kept in a warm 

 place, where they will quickly resume activity. They 

 may be fed on bits of raw meat, preferably fat, of onion, 

 celery, cabbage, etc., thrown on the surface of the soil; 

 and when they are feeding at night, their habits may be 

 observed with a lamp. By hiding bits of food beneath 

 the surface of the soil, the student may determine whether 

 worms have anything corresponding to the sense of smell, 

 enabling them to find food with which they would not 

 ordinarily come in contact. 



Study of a Live Specimen. Place a live worm on a 

 sheet of wet paper, and observe : 



1. In its body 



(a) Definite anterior and posterior ends. 



(6) Correspondence of right and left sides (bilateral 

 symmetry). 



