The Bullfrog, Rana catesbeiana Shaw. 79 



day of the voice-records given in the table were from 62 to 70 degrees, 

 or an average of 67 degrees; for the day previous they ranged from 62 

 to 69 degrees, an average of 66 degrees. 



When croaking begins, the males often take certain perches in which 

 they keep a proprietary interest. Aboutonepond (Plate i, Fig.l) I located 

 seven such places, each with its possessor, only once finding two in one 

 place. The characteristics of the stands can best be told from a list for 

 one pond: the first was on a board in water filled with brush; another 

 was perched on a log among brush beneath a float of a boat-house ; the 

 third was on the bank among some limbs extending into the water; 

 the fourth was by an overturned stump whose roots were partly out 

 of the water and partly submerged; the fifth was among some drift- 

 wood along the shore; the sixth was on a stationary float; and the last 

 was at the base of a tree fallen into the pond. At these stands one 

 could have had good success in capturing the frogs by night. This 

 rule of perches obtains more particularly when the species is not espe- 

 cially numerous in a pond or lake. When, however, the numbers of 

 males about a lake are numerous enough to make their night croaking 

 seem a real chorus, and when they are abundant among the fallen 

 logs and brush of the swampy borders of lakes, it is not likely that 

 any one individual holds a favorite site to the exclusion of the others. 

 In such places one can easily take, in an hour or so, 30 or 40 adults 

 with either flash-light or acetylene light. 



If one wishes to secure them by day he may adopt the familiar red 

 flannel on a hook. At the breeding season one occasionally finds them 

 in grassy situations. Here they lie on the surface. One has only to wade 

 amongst them to capture them by hand. At first they may become 

 frightened, but soon they reappear. Whenever bullfrogs are hard to 

 find or scarce in certain bad seasons let the collector search out a former 

 mill-pond whose dam is gone, and in the temporary small ponds remain- 

 ing he can frequently find the frogs in their circumscribed quarters. 



The males croak mainly at night. In a shady place or while the 

 sky is overcast and the air most oppressive, one will occasionally hear 

 them croaking by day in May or June. In July, however, particularly 

 in the middle of the month, several voice-records of single individuals 

 have been made through the four hottest hours of mid-day. 



THE MATING. 



As with the other Rana males, the first finger of males of this species 

 becomes enlarged. The embrace is in the customary Rana fashion. 

 Of it, we have only one observation two captives, a male and a female, 

 on June 13, 1906. The amplexation was axillary and came after the pair 

 were together two days in a large tank kept dark. About an hour 

 after the beginning of the embrace I attempted to transfer them to the 

 photographic jar and they broke their hold. Evidently the species 



