Bufo fowleri Putnam, in Missouri 7 



than in B. americanus. The under parts of tlie former 

 are generally unspotted, those of the latter usually are 

 spotted. 



Breeding Habits. B. americanus breeds relatively 

 early, B. fowleri relatively late, the breeding season of 

 the former having passed as a rule some time before that 

 of the latter begins. The data for St. Louis are inade- 

 quate, but apparently during the past two years B. 

 americanus has left the breeding sites before the middle 

 of April, while in 1921 a careful watch for B. fowleri did 

 not result in finding any specimens till April 23 and no 

 active breeding until May. At. St. Louis the breeding 

 season extends into June. The Q^g strings of B. fowleri 

 have the eggs arranged in several rows while those of B. 

 americanus are in a single row. 



The Call. The call, or song, of the two species is 

 very different and when both have been heard they are 

 not likely ever to be confused. The song of B. foivleri is 

 a harsh unmusical call with a peculiar initial inflection 

 — an ''unmistakable, w^eird, wailing, scream" (Allard). 

 ** There is no sound in bog, pond, fen, forest or air, at all 

 like it" (Nichols). The average duration of the call 

 both at St. Louis and in Massachusetts is slightly over 

 two seconds, rarely three seconds. The song of B. ameri- 

 canus on the other hand is a prolonged, uninflected trill 

 of a rather pleasant droning quality. Its duration may 

 be for as much as 30 seconds. It is heard only early in the 

 season and may be uttered in relatively cold water. B. 

 fowleri calls only when the temperature is comparatively 

 high. 



It is of interest to note that between these two 

 species, which in some respects are very similar, charac- 

 ters that might be called fundamentally psychological — 

 e.g. habits, notes, — are among the most distinctively dif- 

 ferential. The writer has been impressed with a some- 

 what similar phenomenon among birds, where local dif- 

 erences in song or call notes are far more apparent than 



