10 FAMILIAR LIFE IN FIELD AND FOREST. 



actly imitated by striking two marbles together, first 

 slowly, then faster and faster, for a succession of 

 about twenty or thirty beats. The noise can not be 

 heard at a very great distance. 



The little frog is prominently marked on the 

 back with green, and has the same dark triangle on 

 the crown as that described for the species proper. 

 He remains in the tall grass around the marsh, and 

 seldom if ever ascends a tree or bush. When pur- 

 sued he leaps extraordinary distances and invariably 

 makes for the water, into which he disappears just 

 as we reach the margin after much clumsy slumping 

 through the bog and vain grabbing at the unattain- 

 able. Only one who has lost a frog this 

 way knows anything about the sudden men- 

 tal activity of the baffled pursuer as he 

 stands gazing at the mocking ripples. 



The genus Acris is distinguished for 

 its swimming powers. Look at my draw- 

 Hindieg ing of the hind leg and note the webbed 



iA. gnjllus 



crepitans), toes ; uow comparc this with the hind leg 

 of Choropliiluii t riseriatus (page 11), and it will be 

 seen that the latter can not be much of a swimmer. 



The CJiorophUns triseri((tus, another singer in 

 early spring, about the same size as the cricket frog, 

 may be heard in the West, and in the East as far 

 north as central New Jersey. This frog is ash-gray 



