56 The 



Leopard-frog or Meadow-frog, Rana pipiens (Sckreber). 



The maximum air-temperatures for the day previous to the record (one 

 exception) range from 43 to 76 degrees, or for the day of record (one 

 exception) from 44 to 61 degrees, the averages being 51 and 55 degrees 

 respectively. These are also borne out by second and third records. 



An average date of spawning is about April 1 1 ; our earliest record is 

 March 29, 1910; our latest first record, April 18, 1912. The intervals 

 between first appearance and first spawning range from 7 to 25 days, 

 averaging 19 days. 



In 1908, the species began laying at water-temperatures of 43 to 

 46 degrees, and reached the crest at 60 to 64 degrees. In 1909 it began 

 at 45 degrees and started the crest at 52 degrees. In 1910 the water- 

 surface records range from 55 to 64 degrees, the water-bottoms 52 to 

 64 degrees; the two averages were 59 and 57 degrees. In 1911 the 

 species began at 43 degrees (water-surface and water-bottom) and en- 

 tered the crest at 48 to 58 degrees. An average of water-surfaces is 

 53 degrees, their range 43 to 65 degrees; an average of water-bottoms is 

 51 degrees; their range 43 to 64 degrees; the average of maximum 

 water-temperatures is 59 degrees; their range 54 to 63 degrees; the 

 average of minimum water-records is 51 degrees, their range 45 to 58 

 degrees. An average of all the water-surface records taken gives 55 

 degrees, and of the water-bottoms 53 degrees, or an average of all water 

 records secured from 1908 to 1912 gives 54 degrees. In general, when 

 the maximum air-temperatures indicate 43 to 48 degrees, and certainly 

 when they average 51 to 55 degrees, the meadow-frog begins spawning. 

 The more important and effective temperatures, namely, those of the 

 water, vary from 43 to 46 degrees at the first of the ovulation, and range 

 from 52 to 65 degrees at the crest, the average of the totals for the whole 

 breeding season for 4 years being 54 degrees. 



We have a few unusual records of spawning. Dr. A. A. Allen suc- 

 ceeded in getting mated pairs to lay in a wet handkerchief. At 10 h 20 m 

 a. m., April 23, 1907, a mated pair was captured and brought to the 

 laboratory on the third floor; the next morning the cover of the jar 

 was found knocked off and the pair had escaped. In an hour we 

 found the trail of the pair. Halfway down the staircase between the 

 second and first floors was a bunch of eggs H inches in diameter, no 

 expansion of the mass being possible. 



