DELAWARE COUNTY FROGS. 15 



It is believed to subsist principally upon green algae, such as 

 that called "frog spittle" and upon the microscopic over- 

 growths of the same, like infusorians and diatoms. But it 

 will take meat at times. Last summer I observed in a pool 

 near home the body of a large frog. This frog was but too 

 evidently dead, yet it seemed to move in a spasmodic manner. 

 When it was stirred up with a stick a dark brown stream of 

 panic stricken tadpoles came out of its gaping mouth. They 

 had been gorging themselves upon the body of the departed. 

 Now this was a wide departure from vegetarianism, and 

 amounted to practical cannibalism. 



The identification of the different species when in the tad- 

 pole state is possibly within the power of an expert, but it 

 can scarcely seem easy to any one, and certainly not to an 

 amateur whose ol)servations are only casual. The tadpoles of 

 the common toad, however, are easily distinguishable. The 

 transformation into the frog would seem to take place, as a 

 rule, before the end of the first summer. But certainly this is 

 not always the case. Very large tadpoles, possibly those of 

 the bull frog or the large green frog, may be seen huddled 

 together in the depths of a frozen pond in mid-winter. The 

 transformation, once begun, goes on rapidly, and a legless, 

 gill-breathing creature becomes a thing of legs and lungs 

 within three weeks from the first budding of the hinder limbs. 

 It would seem a wondrous change for such a space of time. 

 The tail is gone, the feet have all their exquisite little toes, 

 the small, round mouth has expanded into the generous, ear- 

 to-ear afi"air we know so well. The creature has now a voice, 

 and knows how to use it. He is altogether another being. 



Our frogs, how numerous soever in individuals, seem all to 

 belonu to the following species : ^' 



Raiia catesbiana, Shaw. Bull Frog 

 " clamata, Daudin. Green Frog 



' * For technical (le>criplions of the species, the learner is referred to 

 David Starr Jordan's excellent " .Mantial of the Vertebrates." 



