620 Home Nature-Study Course. 



if kept in a dry atmosphere. The toad makes its home by burrowing in the earth. 

 It has a peculiar method of kicking its way backward into the earth until nothing 

 but its head shows. Then if an enemy comes along, back goes the head, the earth 

 caves in around it and no toad is to be seen. It remains in its burrow or in its 

 hiding place usually during the day and comes out at night to feed. This may be 

 an advantage because the snakes are then asleep, and the snake is its most feared 

 enemy ; and too, there are many insects that are out at night. Perhaps the best 

 place to find toads is in the vicinity of the street lights where they gather in 

 numbers to catch the insects which swarm there. In winter the toad buries itself 

 deeply in the ground and goes to sleep remaining in this dormant state until 

 the warmth of spring wakes it up, and then it comes out and goes back to its 

 native pond, there to lay the eggs for the coming generation. The song of the 

 toad is a pleasing, crooning sound, a sort of a gutteral trill. When singing the 

 throat of the toad is puffed out ; this extension of the throat is called a vocal sac. 

 It is filled with air which is drawn in through the mouth and it acts as a resonator. 

 The sound is caused by the passing of air through the vocal cords in the throat; 

 the air is drawn in at the nostrils and is passed back and forth from the lungs to 

 the mouth over the vccal cords. While breathing we can see the throat move in 

 and out. This is caused by the movement made in swallowing the air and forcing 

 it into the lungs. The toad has no ribs by which it can inflate the chest, and in 

 that way draw air into the lungs as we do. It is, therefore, obliged to force the 

 air into the lungs by swallowing it. The toad has many enemies; chief among 

 these is the snake ; crows also and other birds prey on toads. As the toad grows 

 it sheds its horny skin, which it swallows; however, this shedding of the skin is 

 usually done in private, and the ordinary observer sees the process but seldom. 

 The toad enjoys very much having its back scratched gently. 



LESSON LXIX. 

 THE FROG. 



Purpose. — To call attention to the appearance and habits of the frog. 



Material. — A frog in an aquarium in wliich there is a stick or stone 

 projecting above the water. Any species of frog will do but the common 

 spotted or leopard frog is a particularly attractive object for study. So 

 also is the common green frog. 



Observations. — 



(i). Where was the frog found? 



(2). Where does it live? 



(3). When found on land how does it seek safety?" 



(4). Compare the form of a frog with that of a toad. 



(5). Describe the skin, its color and texture. 



(6). Compare the skin of the two. 



(7). Compare the colors of the two above and l)elow. 



(8). Describe the colors and markings of the frog. 



(9). Describe the eye, ear, nostrils and motith. 



(10). Compare the hands and feet of the frog with those of the toad. 



(11). Why the dififerences in the feet? 



(12). What is the feeling to your hand when you init it on a frog? 



(13). How does the slipperiness of the frog help it? 



