28 The American Toad, Bu/o lentiginosus americanus LeConte. 



most of May they may be heard by day even during its hottest portions. 

 After May 20 their daily notes practically cease. At night their trills 

 reach far into the summer, e. g., in 1910 they were heard until June 

 26, in 1907 until July 15. Water-temperatures taken at the time of 16 

 voice-records in 1909-1911 show that the species begins piping when 

 the water reaches 53 to 60 degrees. 



The species, then, begins trilling usually at 60 degrees, though records 

 as low as 50 degrees have been secured, the averages being from 62 to 

 66 degrees. They enter the chorus at 69 to 71 degrees. The effective 

 water-temperatures seem to be from 53 degrees upward, their average 

 being over 60 degrees. 



THE MATING. 



The males are noticeably smaller than the females (Plate u, Fig. 1), 

 have dark throats, and at the breeding season possess dark-brown 

 excrescences (Plate in, 86) , on the inner-upper side of the first two fing- 

 ers (rarely on inner edge of third finger) and on the inner carpal tubercle. 

 In color they average lighter, but as considerable mating takes place 

 by day and in shallows, the females are often as light as their consorts. 

 Both sexes repair to the water about the same time (the males slightly 

 preceding) , a condition that does not so generally obtain with the other 

 Anura of Ithaca. At this migrating season, some of the paths, walks, 

 and roads are almost completely covered with toads. The two sexes 

 are commingled and frequently the male makes the journey on the back 

 of the female, neither seeking cover during the daytime. Sometimes, 

 in the early season, before the species has reached the crest of breeding, 

 one can find hidden males at varying distances from a breeding spot. 

 In little sunken pockets at the surface of the ground, they occasionally 

 hide, not entirely under cover. The back is exposed to the sun and the 

 skin is as dark as the dirt itself. The migrations begin early in April, 

 but toads have been recorded migrating to breeding localities as late 

 as June 14, by which date many of the early breeders are leaving or 

 have left the ponds. 



The males far outnumber the females, and the furious actions inci- 

 dent to the first meetings of the two sexes, or following the arrivals of 

 other toads, are long-sustained and exhausting. Often five or more 

 males are attached to one female, or else to each other in their attempt 

 to reach the female. Not rarely do some of the females in such bunches 

 die from suffocation and pressure. 



Normally, the pair, if mated in water, lays at once. With every one 

 of the numerous captive pairs we have secured ovulation on the day of 

 capture or during the following night. Of course, where they meet on 

 the migration, the male may be mated more than a day; but, when the 

 water is reached, the embrace does not last long before eggs are laid. 

 Rarely, after mating takes place, a sudden drop far below the normal 



