84 
LABORATORY EXERCISES 
nature of the body covering? What variation do you find in the 
fur on different parts of the body? Compare the fore and hind 
legs as to their size and use. Examine the feet. What are the 
number and nature of the toes? Of what use are the claws? Note 
the character of the under side of the feet. Note the size and 
location of the ears. Watch their movements. Observe the eyes. 
How many eyelids do you find? What is the nature of the front 
teeth? These teeth continue to grow throughout life. Since the 
outside is much harder then the inside, the inner portions wear 
away more rapidly than the outer, and the teeth remain sharp. 
What is this animaPs food? How are the teeth adapted for the 
use of such food? 
EXERCISE 83 
INTERRELATIONS OF THE LIFE ABOUT A POND 
I. Field Study. Make a survey of all the living forms in the 
pond or within three feet of the edge of the water. Collect speci¬ 
mens of each form. Let certain members of the class act as re¬ 
corders. These recorders may make a note of the places where 
the specimens are found and of any activities observed before they 
are collected. 
II. Laboratory Study and Conference. Identify the specimens 
which have been collected and determine the groups to which 
they belong. Look up their food habits. (See Needham and 
Lloyd, Life of Inland Waters.) Arrange the report in a table as 
suggested below: 
Pond Life 
Name 
Animal or 
PLANT 
Group 
Where found 
Food 
(Example) 
Whirligig 
beetle 
Animal 
Insect 
Surface of water 
Small insects which 
fall into the water 
