1925] Storer : A Synopsis of the Amphibia of California 281 
description given by Wright (1914, pp. 82-83) for the first-season 
tadpole of Rana catesbeiana, save that they were smaller. A spawn- 
ing date in midsummer is indicated in this case. 
The Bullfrog in the eastern United States requires two full years 
(sometimes more) in order to complete its larval development. The 
situation in this respect in California is, inferentially, the same ; direct 
observation is as yet to be made. According to Mr. Edmund C. Jaeger, 
high school students at Riverside stated that tadpoles in that neigh- 
borhood require two years to change into frogs. Further evidence of 
a lengthened larval life is furnished by material obtained by the writer 
in Sonoma Creek at Agua Caliente, Sonoma County, on August 27, 
1922. On this date there were, in the pools of the creek, tadpoles of 
three distinct sizes. (The largest measured 135 millimeters in total 
length ; and these all had fully developed hind legs and in many the 
forelegs had already burst through the opercular membrane.) The 
second category comprised tadpoles about 50 millimeters in total 
length, but without hind legs. Both of these lots of tadpoles were 
olive green in general coloration, wuth many fine black dots. The 
third lot was of very small tadpoles, about 12 to 15 millimeters in total 
length, of a generally black coloration with scattered yellow markings 
and an angular cross-mark on the back behind the eyes. 
These three sizes of tadpoles correspond to the two-year-old, one- 
year-old, and newly hatched tadpoles of Rana catesbeiana as described 
by Wright. The inference seems justified that they represent egg 
masses laid in 1920, 1921, and 1922, respectively, and that the life- 
history of the Bullfrog in California is therefore essentially like that 
in the eastern states. So far as known, the only native California 
frog which regularly spends more than one season in the larval stage 
is Rana boylii sierrae. 
The life-history in relation to the environment. — The introduction 
of the Bullfrog into California, while done in the first instance by 
laymen intent upon adding a desirable species to our rather meager 
frog fauna, is likely to provide, as an unintended by-product, material 
for an interesting study on the relation of the life-cycle of a species 
to its environment. The case is somewhat parallel to that afforded by 
the introduction of the English Sparrow, as recently discussed by 
Grinnell (1919). Fortunately the several localities into which the 
Bullfrog has been introduced are situated in several distinct biological 
regions of California: on the Mohave Desert, in the San Joaquin 
Valley, in the Sierran foothills, and in the Coast Ranges. As yet 
