34 The American Toad, Bufo lentiginosus americanus LeConte. 



able when they leave the shores and cross near-by roads and streets. 

 Transformation begins the last of June and may continue into August. 

 Our earliest record of transformation is June 8, 1911. In 1906, our first 

 record is June 23; in 1907, July 4. An average date is about June 21. 

 The curve of 182 transformed individuals gives a range of 7 to 12 

 mm., an average of 9.6 mm., a mode of 10 mm. (Plate x, Fig. 1.) 



THE AUTUMNAL DISAPPEARANCE. 



The toad is observed quite commonly in September; but, as the 

 colder days of October begin to appear, it goes, for varying periods, into 

 its hiding-places, burrows, and covers, especially after the first hard 

 frosts. Thereafter, occasionally during the warm spells (above the 

 average for October days) it reappears. Most of our late records are in 

 the month of October, the latest being November 4, 1907, the average, 

 about October 20. The average maximum air-temperature for the 

 day before the record is 66, as it is for the day of the record. For the 

 day of the record and that preceding, the maxima are above 57, with 

 the two following exceptions : In one instance, the temperature was as 

 low as 48 on the day the specimen was found, but on the day previous 

 it reached 67. The record of November 4, 1907, was flanked by 50 

 on either side. It therefore appears that the species may be observed 

 in the fall, after it has retired one or more times, provided the tempera- 

 tures ascend to 60 to 66 degrees. It has been recorded, however, under 

 the temperatures of 48 to 57 degrees. 



