VERMES. 33 



I. liocomotion. 



1. Identify the setae on the ventral surface of a living 



earthworm. (If you cannot see them, feel for them.) 



2. How many rows of setae are there ? How many setee 



on each somite ? 



3. In locomotion what is the use of the setae ? 



4. How is locomotion accomplished ? 



5. Can an earthworm crawl up a vertical surface ? 



(Place earthworms in a deep glass dish and keep 

 the sides of the dish wet. Devise other tests also.) 



J. Burrowing'. 



Place an earthworm upon earth which has been 

 slightly pressed down and observe its m&thod of 

 burrowing. 



1. How is the burrow made ? 



2. How is the earthworm adapted to this work ? 



3. Does the earthworm avoid the light? (Place a 



small earthworm in a moistened tube one half of 

 which has been covered with black paper. Repeat 

 several times.) 



K. Drawings, Diagrams and Models. 



1. Draw the dorsal view of an earthworm. 



2. Make a diagram of three somites of the ventral 



surface to show the position of the setae. 



3. Cut out a paper model of a cross-section of the earth- 



worm. Color the model, using red for blood- 

 vessels and muscles, blue for nerves and epidermis, 

 and yellow for the alimentary canal. 



4. Cut out a paper model of a medium longitudinal sec- 



tion in the dorso-ventral plane showing the body 

 wall, the septa and the alimentary canal, disregard- 

 ing modifications. 



