134 AMPHIBIA (the frog) 



(2) What color is the frog as seen by animals below it? 

 Purpose of this color? 

 (g) Eggs. Look among the leaves and trash in the edge 

 of the water for the egg masses or spawn — lumps 

 of jelly-like material containing the eggs. Take 

 these to the laboratorj^, place them in water where 

 there is no danger of their being eaten, and watch 

 their development. 

 (h) Take also large frog's, which may be captured with 

 the hook if they cannot be gotten with the net. 

 2. Laboratory Study. 



Place a number of frogs in a tank or tub covered with a heavy 

 wire screen, and containing an inch or two of water. 



(1) Try various kinds of food, as live insects, bits of meat, 



tadpoles, bread, grass, etc. 



(a) Which kind of food does the frog prefer? 



(b) How does it take its food? 



(c) Has it any special adaptation for catching insects? 



If so, what? 



(2) Observe its methods of locomotion. 



(a) In shallow water or in no water. 



(b) In deep water. 



(c) Can a frog walk? 



(d) How far can it jump? 



(e) What adaptations has it for jumping? 



(3) What is the position of a frog at rest? 



(4) How does it breathe? 



(5) Notice the pulsations of the ''lymph hearts" on each 



side near the end of the backbone. 



(6) What means of defense or escape has the frog? 



(a) Molest it from the front. What does it do? 



(b) Molest it from behind. What does it do? 



(7) Eyes. 



(a) Are there eyelids? If so, are the upper and lower 



lids alike? 



(b) Observe and describe the movements of the eyelid. 



(8) Voice. 



(a) Do the different species have different voices or calls? 



(b) Do they cry out in fright? In pain? 



