48 STUDIES OF ANIMAL LIFE. 



1. Feeding. 



Tempt a crayfish to eat. (It is difficult to get the 

 crayfish to eat in captivity. Try small bits of 

 liver or fish.) 



a. What appendages are used in handling the food 



and in passing it to the mouth ? 



b. What, if any, appendages are used in breaking or 



cutting the food ? 



c. Describe the process of feeding. 



d. Does the crayfish like some kinds of food better 



than others ? 



e. Can the crayfish tell its food from other sub- 



stances ? 

 What is the natural food of the crayfish ? 



2. The Sense of Feeling. (Touch.) 



a. With a bristle test the sense of feeling in various 

 parts of the body, — the shell, appendages, eyes, 

 " feelers," setse, etc. What parts of the body 

 are most sensitive ? 



h. Observe the movements of the crayfish with a 

 view to discovering the use of the antennae. 

 Record observations. 



c. How are the antennae carried when the crayfish 



is at rest ? When the crayfish is in motion ? 



d. What work can you suggest for the antennules 



that cannot be done as well by the antennee ? 



3. The Sense of Smell. 



a. Test the sense of smell by using some pungent 



substance. (Dem.) 

 h. Where is the sense of smell located ? 



4. The Sense of Taste. 



a. Test for this sense by placing some sour or bitter 

 substance on the mouth parts. (Dem.) 



