76 The Green-frog, Rana clavmta Daudin. 



THE LARVAL PERIOD. 



In 1906, transformed examples were recorded June 28. If in 1905 

 the species first began laying in June, as it usually does, we get a period 

 of one year from egg deposition to transformation. In another pond 

 the larvae of 1906 began to transform June 28, 1907, and new eggs were 

 recorded June 21, 1907. If in the previous year egg-laying occurred 

 about the 21st of June, Ave have about a year for the interval between 

 egg-deposition and transformation. In a small pond where the species 

 first laid June 6, 1906 (this bunch being the only eggs laid in the pond 

 during the season), the first records of transformation in 1907 were 

 July 13, thus giving 372 days before transformation. In 1908 tadpoles 

 were transformed July 21, or 400 days after the eggs were deposited. 

 In 1910 eggs were laid in a certain pond June 9; and on June 29 of the 

 succeeding year (1911) the tadpoles began to transform, 385 days later. 

 The period, then, appears to be from 370 to 400 days. 



THE TRANSFORMATION. 



Most of our records would bring transformation in the latter part of 

 June and through JulJ^ Our first dates are: June 17, 1902; June 28, 

 1906; June 28, 1907; July 21, 1908; July 10, 1909; and June 29, 1911. 

 The average of all is July 3, though June 28 is the more correct date. 

 This makes the green-frog third in the order of transformation, the 

 toad and wood-frog preceding it. Usually, by the first of August, 

 transformation for the species is largely but not wholly completed. 

 In a species which lays from the last of May to the middle of August or 

 later, it is evident some transformations may range within the same 

 limits. The size at transformation of 41 specimens varies from 28 

 to 38 mm.; the average is 32 mm.; the mode is 31 mm. 



THE AUTUMNAL DISAPPEARANCE. 



During the most of October and earl}^ November, one often sees 

 the green-frogs around the edges of ponds with Rana pipieris. These 

 two very often hibernate in the same pond and in the same manner. 

 Most of our records of late appearances come in the very last of October 

 or the first week of November. An average of the latest dates of 

 appearance is about November 3, our latest record being November 11, 

 1899. The average air-maxima for the day before and for the day of 

 the record are 67 and 69 degrees and the minima 38 and 42 degrees. 

 When the temperatures of late October or early November reach the 

 above maxima, the green-frogs often come out, though they may have 

 previously sought cover. They hibernate in the mud of our marshes 

 and ponds. In the ravines they often seek winter-quarters underneath 

 a submerged stone or kindred cover, occasionally under dead wet 

 leaves of our stream beds. Not infrequently do we record them in 

 the middle of the winter, provided thej^ chose a spring for hibernation. 



