366 



NATURAL HISTORY. 



Some of the young, kept in confinement, dug their oval oblique holes in 

 the sand, almost all of them disappearing below the surface in twenty 

 minutes. Concerning the note made by this species Dr. Abbott says in 

 another place : " So unlike the cries of any other of our batrachians were 

 their utterances that all who heard them were attracted to the spot, and 

 wondered, when they saw the animals, that so great a volume of sound 

 could proceed from so small a creature. One need not wonder, however, 

 on this point, if they will examine the development of the animal's vocal 

 cords. The machinery for producing sounds equal to an ordinary steam- 

 whistle is apparently contained in the throat of this rare and curious 

 batrachian.'' 



The tree-toads are elegant forms adapted for an arboreal life. The 

 ends of their fingers and toes are expanded into broad discs, to the better 

 enable them to adhere to the leaves and branches of trees, while their 

 colors are such as to conceal them from observation. Indeed, they have 

 the power to change their colors to a considerable extent in order to agree 



more closely with their sur- 

 roundings ; and our com- 

 monest species will be dark 

 brown or ashy gray when 

 on the trunk of a tree, but 

 when found among the 

 leaves it is green. The 

 tree-toads are strong and 

 usually pleasing singers, 

 some of them furnishing 

 the shrill ' pee-wee ' of the 

 early spring, while others 

 are heard later in the year, 

 or indeed during the whole 

 season, until the time for 

 hibernation comes round. 

 There occurs in the Ma- 

 layan Islands a very peculiar frog which is called the flying-frog. Mr. 

 Wallace, its discoverer, describes it as follows : " One of the most curious 

 and interesting reptiles which I met with in Borneo was a large tree-frog, 

 which was brought me by one of the Chinese workmen. He assured me 

 that he had seen it come down, in a slanting direction, from a high tree, 

 as if it flew. On examining it I found the toes very long, and fully 

 webbed to their very extremity, so that when expanded they offered a 

 surface much larger than the body. The five legs Avere also bordered by 



Fig. 335, — Tree-toad (Acris gryllus). 



