Many observers have noted that breeding activity is initiated by heavy rains in summer. In my experience precipitation of at least two inches within a few days is necessary to bring forth large breeding choruses. With smaller amounts of precipitation only stragglers or small aggregations are present at the breeding ponds. Tanner (1950: 48) stated that in three years of observation, near Lawrence, Kansas, the first storms to bring large numbers of males to the breeding ponds occurred on June 20, 1947, June 18, 1948, and May 1, 1949. In 1954 the frogs were recorded first on April 25, but these were under massive boulders, and were still semi-torpid. Frogs were found fully active, in numbers, under small flat rocks on May 7. They were found frequently thereafter. On the afternoon of May 13, the third consecutive day with temperature slightly above 21° C., low croaking of a frog was heard among rocks at an old abandoned quarry. Throughout the remainder of May, calling was heard frequently at the quarry on warm, sunny afternoons. Often several were calling within an area of a few square yards, answering each other and maintaining a regular sequence. In the last week of May rains were frequent, and the precipitation totalled 2.09 inches. On June 1 and 2 also, there were heavy rains totalling 2.26 inches. On the evening of June 2 many frogs were calling at a pond ½ mile south of the Reservation, and one was heard at the pond on the Reservation. By the evening of June 4, dozens were calling in shallow water along the edge of this pond in dense _Polygonum_ and other weeds. There was sporadic calling even in daylight and there was a great chorus each evening for the next few days, but its volume rapidly diminished. In mid-June a system of drift fences and funnel traps was installed 200 yards west of the pond in the dry bottom of an old diversion ditch leading from the pond. The ditch constituted the boundary between bottomland pasture and a wooded slope, and therefore was a natural travelway. The object of the installation was to intercept and catch small animals travelling along the ditch bottom. The drift fence was W-shaped, with a funnel trap at the apex of each cone so that the animals travelling in either direction would be caught. The numbers of frogs caught from time to time during the summer provided information as to their responses to weather in migrating to the pond. TABLE 1. NUMBERS OF FROGS CAUGHT WITHIN TWO DAYS AFTER RAIN IN FUNNEL TRAPS IN 1954, FROM MID-JUNE, TO THE TIME OF FIRST FROST.