The Bullfrog, Rana catesbeiana Shaw. 85 



which are both widely separated and distinct. Occasionally the}'- have 

 white or light centers and some of these, as in the one and two year 

 old tadpoles, are dumb-bell-shaped or linear. The throat and chin are 

 translucent with a few black specks. The belly is one uniform bronzy 

 iridescent coat (like the wood-frog tadpole's venter). This iridescence 

 continues on to the gill region of either side, breaking into irregular 

 patches which are deeper seated than the large groups of gilt spots 

 ivhich extend across the gill region from one eye to the other. The eye is 

 black with bronzy speckings. Tail: Translucent. The very fine and 

 dark pigmentation of the body background extends on the tail. The 

 yellow-grouped spots are scarce and mainly at the base of the muscular 

 part of the tail. The black circular spots are also few and show a 

 greater tendency to the dumb-bell-shaped form than those on the body. 

 The smaller size, fine-speckled (salt-and-pepper effect) bodies, and 

 lack of the striking light olive-green of tadpoles one and two years old, 

 together with a venter wholly unlike these, make the tadpoles of the 

 first season easy of identification. In 1912 some tadpoles of the first 

 season, second season, and maturity were collected at the same time 

 and place. The first-season forms measured in length 30 to 35 mm. ; 

 the second-season specimens, 75 to 90 mm.; the mature forms, 100 to 

 145 mm. 



THE LARVAL PERIOD. 



The species spends two winters in the larval stage. Inasmuch as 

 the eggs are small and deposited late in the season (usually last of June 

 or in July), the tadpoles are small when winter arrives. The whole of 

 the next season is consumed in growth, and it is not until another winter 

 is passed that the larvae begin to approach transformation, which 

 usually comes in July, i. e., two years after egg-deposition. More 

 rarely does the tadpole spend a third winter before transformation. 

 Along one mill-pond (shores abrupt, 2 to 5 feet deep), on August 26, 

 1912, we secured, in the fine-matted rootlets of old weeping- willow 

 trees, 100 two year old tadpoles, transformed, transforming, and some 

 which clearly could not transform within two months if at all before 

 winter came. In the same situation we took only 4 of the one j'^ear old 

 forms, and some 20 to 30 of the first-season tadpoles (1| to 2| months) . 



THE TRANSFORMATION. 



All our data of transformation comes in July or later. In 1906 the 

 species was recorded as transforming July 16 and 24; in 1907 it was 

 during the last of July; in 1909 transformation was at its height July 

 16 to 18; in 1910 on July 30; in 1911 it was July 8 to 14 and later; and 

 in 1913 it reached from July 3 far into August. An average of the 

 first dates places the beginning of transformation at July 15. The 

 species evidently does not begin transformation before July 1, often 

 extending to August 15. In 1910, when first recorded July 30, there 



