1086 Rural School Leaflet 



ing organ, passage of oxygen into the blood taking place through the 

 skin as well as through the lungs. Such forms should always be kept 

 moist because the exchange of gases cannot take place if the skin becomes 

 dry. For the same reason prolonged handling will kill most amphibians. 



5. Study the color of the Peeper. Is it always the same? Keep the 

 Peeper in a cool, dark place for some time and then bring him into the 

 bright sunlight. Does any change take place, and how long does it 

 require? What is the purpose of this change? 



6. Catch some flies or other small insects and put them into the jar 

 alive. Try to learn how the Peeper catches his food. He may not eat 

 until after you have had him for some time. 



7. In order to study the development from the egg it will be much 

 easier to select some other species. The common toad is most satisfac- 

 tory, because the eggs are least difficult to find and the shortest time is 

 required for completing the process. 



8. If not already familiar with the notes of the Peeper, one will learn 

 them most easily early in the season before the appearance of the other 

 amphibians. The Peepers appear in March, soon after the disappearance 

 of ice from the ponds. If what has been said concerning the notes be 

 borne in mind, one should have no difficulty in recognizing them. The 

 notes of all the frogs are low and guttural; those of the toads are shrill 

 and high, but continuous trills. In the western parts of the State another 

 tree-frog, the swamp cricket frog (Chorophilus triseriatus) is also abundant 

 and resembles the Peeper somewhat closely. It can be easily distin- 

 guished by the absence of the oblique cross on the back and by the small 

 size of the viscid disks. The note of the swamp cricket frog, although 

 similar to that of the Peeper, differs in that the individual notes, although 

 short, are always tremulous, while those of the Peeper are sharp and 

 entirely free from this quality. 



9. Note the temperature of its body and see whether there is a change 

 after the Peeper has been for some time in the sunlight. Amphibians, as 

 well as reptiles and fish, are known as " cold-blooded " animals. Their 

 blood is not, however, always colder than that of the higher animals. 

 The chief difference is that " warm-blooded " animals have a constant 

 temperature and " cold-blooded " animals have a temperature that varies 

 with that of the environment. 



Note. — In speaking of peepers that he found, Thoreau says: " I keep them in a 

 tumbler. Peep at twilight and evening, occasionally at fit her times. One that got 

 out in the evening onto the carpet was found soon after by his peeping on the piano. 

 They easily ascend the glass of the window; jump eighteen inches and more; * * * * 

 will sit half a day on the side of a smooth tumbler; make that thrilling note in the 

 house; remain many hours at the bottom of the water in the tumbler, or sit as long 

 on the leaves above." 



