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Home Nature-Study Course. 



LESSON LXX. 



THE TREE FROG. 



Purpose. — To make the pupils accjuainted with the appearance and 

 habits of this interesting little creature. 



Material. — A tree frog in a moss garden in an aquarium in which a 

 thick twig may be placed in an upright position. 

 Observations. — 



(i). What are the chief 

 differences between the tree 

 frog and other frogs ? 



( 2 ) . How does tlie tree 

 frog climb? 



( 3 ) . How does it man- 

 age to make the discs on its 

 toes cling and then let go? 



(4). \\\\\ it remain vol- 

 untarily head down ? 



(5). How does it look 

 when peeping? 



(6). What do tree frogs 

 eat? 



( 7 ) . \Aniere do they live ? 

 (8). How do the eggs of 

 Tree frog tadpoles. the tree frog look? 



(9). How do the tree frog-tadpoles look? 

 (10). Of what use are tlie tree frogs to us? 



Facts for teachers. — The tree frog is much smaller than the other frogs, and 

 its toes and fingers are provided at the ends with round discs, by means of which 

 they can cling to a smooth surface. These discs do not act as suckers as so many 

 people think; but a sticky substance is secreted on their lower surface, and it is 

 by the means of this the tree frog clings. 



The tree frog on a vertical surface will not willingly remain head down- 

 ward, but will always turn aliout so that tlie head is directed upward. When it 

 is peeping the vocal sac under the throat swells out until it is almost globular. 

 The tree frogs live upon insects, almost any insect of proper size that comes 

 near them. They live in trees or on shrubs or vines; in fact, they live almost 

 any place where they can hide under leaves and find jdcnly of insects. The eggs 

 of the spring peeper are laid in ponds during April ; each egg has its one little 

 globe of jelly about it and is fastened singly to water plants. The tadpoles are 

 small and delicate. The under side of the body is reddish and shines with metallic 

 lustre. They differ from oilur tadpoles in that they often leave the water while 

 the tail is still quite long. In June they may be found among the leaves and moss 

 on the lianks of ponds. They are indefatigable in hunting for gnats and mosqui- 

 toes and ants. Their destruction of mosquitoes as pollywogs and adult frogs ren- 

 ders ihem of great use to mankind. 



