70 



The Gh'een-frog, Rana clamata Daudin. 



LIFE-HISTOKY OF THE GREEN-FROG. 



The green-frog and the bullfrog are our most solitary species. The 

 structural differences which differentiate the two are emphasized in 

 the account of the latter. In habitat the green-frog is not so restricted 

 as the bullfrog. Both occur in swamps, and in our deeper, larger 

 ponds and reservoirs. In the smaller ponds and pools only the green- 

 frog is present. In fact, along our watercourses, there is hardly a small 

 pond which can not claim a green-frog. In the swamps only Rana 

 pipie?is exceeds it in abundance. The latter, like the toad and peeper, 

 often inhabits the less permanent situations; the green-frog usually 

 chooses deeper, more permanent bodies of water. 



THE FIRST APPEARANCE. 



The green-frog is our fourth Rana and sixth Anuran to appear in the 

 spring. It usually appears about two weeks after the peeper, and 3 days 

 after the pickerel-frog, the fifth Anuran to emerge. Our records of first 

 appearance are: 



Of these six records, two were of individuals not out of hibernation 

 of their own accord. The first record of 1905 w^as of two torpid indi- 

 viduals under a large stone for cover. The third record (1907) was of 

 a specimen raked out of the mud of one of our ponds. An average 

 date of appearance is April 7, the range being from March 28 to 

 April 20. An average of the maximum air-temperatures for the day 

 of the record is 66 degrees, or 61 degrees if the 1905 and 1907 records be 

 included; for the day before the record, 66 or 61 degrees. In the 

 pertinent records, no maximum goes below 56 degrees. Generally a 

 week intervenes between these first records and their second appear- 

 ance, which comes about April 14. Air-temperatures taken the day 

 before and on the day of the second record yield averages of 54 and 

 69 degrees respectively. It seems that air-temperatures from 54 to 61 

 degrees usually find the species out of hibernation; and when at 61 

 to 69 degrees, the species begins to come out more commonly. The 

 water temperatures of first and second appearances range from 46 to 

 58 degrees or higher. Inasmuch as the species hibernates in water, 

 these water-records are the important factors of emergence. 



