73 



that Dr. Kirtland iufonned him that they were so abundant in the 

 woods of Ohio that it was ahnost impossible to move without stepping on 

 them. With us, at the present day, they are far less abundant. They 

 are extremely active, and when pursued, they escape by making great 

 and quickly repeated leaps. They are very skillful in hiding, and the 

 close resemblance of their colors to the dead leaves and grass surround- 

 ing them renders it extremely difficult to find them. One tliat I was 

 after leaped into the water and hid along side of a stone, and although 

 I knew almost exactly where it was, it was some time before I could 

 recognize it. 



Miss Hinckley has studied the habits of the breeding adults and of 

 the young (^5, xxii, 91 ; 22, xviii, 151). These frogs congregate very 

 early in the spring for the purpose of ovoposition, although they are 

 not able to move in water below a temperature of 45° F, There may 

 be as many as 1,380 eggs in one mass. The time of development varies 

 greatly according to the temperature. The external gills were devel- 

 oped within two days after hatching, and in four more were wholly 

 absorbed. The metamorphosis of the tadpoles was prolonged from April 

 12 to June S). Tadpoles, which on May 31 measured 58 mm. in length, 

 became reduced after the metamorphosis to 18 mm., about three-fourths 

 of an inch. It was first observed by Prof. S. F. Baird that the tadpoles 

 of this frog are carnivorous. He says that one way of preparing the skel- 

 eton of small animals is to put them in a vessel of water containing the 

 living tadpoles of some of our frogs. These will devour the macerating 

 flesh and leave the bones cleaned and hanging together by the ligaments. 

 "The larvte of R. sylvatiea are, he said, the most effective. 



