326 HAROLD CUMMINS 



connected at right angles to the main fence. The lower edge of 

 the cloth, both of fence and leaders, was imbedded in the soil 

 and fastened with wire pins. Underneath the junction of the 

 main fence with each leader a 2-gallon pail was sunk to the ground 

 level and kept half filled with water. The apparatus proved to 

 be very effective. Frogs apparently did not perceive its pres- 

 ence until actually in contact with the cloth. When a frog 

 approached the vicinity of a leader but a short time elapsed 

 before he dropped into the pail, with no chance of escape. If 

 the frog came in contact with the main fence at some distance 

 from a leader, he usually moved along the fence and was even- 

 tually trapped in a pail. But a less active individual might 

 remain nestling in the angle between the fence and the ground. 

 A careful examination of the fences and pails was made at least 

 twice each day, morning and evening, the catch was recorded, 

 and the frogs were transferred to terraria for observation. The 

 fence was originally planned to completely enclose a smaller 

 pond. Because the ice first disappeared from the larger pond, 

 more exposed to the sun, the plan was altered, allowing only a 

 partial enclosure of the larger pond. Future work of this sort 

 should be done with the observation pond completely enclosed, 

 thus ensuring the trapping of all migrating frogs. 



The frog fauna of White's Wood includes the leopard frog 

 (Rana pipiens Shreber), the wood frog (Rana cantabrigensis 

 Baird), the pickerel frog (Rana palustris Le Conte), the green 

 frog (Rana clamitans Latreille), the swamp tree frog (Choro- 

 philus nigritus Le Conte), the spring peeper (Hyla pickeringii 

 Holbrook), and the common tree frog (Hyla versicolor Le Conte). 

 Migration data for the leopard frog, wood frog, swamp tree frog, 

 and spring peeper were obtained, but for sex recognition work 

 pnly the first two species were used. 



MIGRATION 



With the approach of spring, frogs desert their hibernation 

 quarters for breeding places. Doubtless many of them hibernate 

 in the mud at the bottoms of the same ponds where they breed. 



