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University of California Publications in Zoology [Vol. 27 
The voice of the Bullfrog is the loudest of any of the North 
American amphibians. The notes have been reported as being heard 
in most of the California localities into which the species has been 
introduced; indeed, people, living at Loma Linda, Riverside County, 
are said to have complained of the noise made by the frogs introduced 
near that place. No first-hand account of the voice of the Bullfrog 
is available from California, so a description given by Dickerson 
(1906, p. 232) may be quoted in part. 
The Bullfrog does not sing in chorus; the call is an isolated one. The notes 
are so low in pitch that we think of him as the bass viol among the batrachia. 
The call resembles, to a considerable degree, the roar of a distant bull but it has 
a more musical ring and the notes are less blended and slurred. The pitch varies 
with the individual. . . . The call can be imitated well by saying with a hoarse, 
deep-toned voice the syllables of various interpretations of it, such as, ‘Be 
drowned/ ‘Better go round/ ‘Jug o’ rum/ or ‘More rum.’ The imitation is 
especially good if the slurred words are repeated in front of some reverberating 
hollow body. 
The Bullfrog has also, according to this and other authors, a loud 
prolonged high-pitched scream, uttered when the frog is seized by 
some large enemy. 
No eggs laid in California have been available for study. The 
following description is condensed from an extended account by 
Wright (1914, p. 82), who studied this species* at Ithaca, New York. 
The eggs are deposited in pond water of varying depth, usually 
around brushy material in the water. The egg mass is typically of 
disc form, loose in texture, and covers more than a square foot of 
area; exceptionally it may occupy as much as five square feet. Less 
often the eggs are deposited in stringy filaments. The complement 
may be from 10,000 to 20,000 eggs. The individual egg has a black 
animal pole and white or creamy white vegetative pole. The vitelline 
capsule usually measures 1.2 to 1.4 millimeters in diameter. There is 
no distinct middle envelope of jelly as with native California frogs, 
and the outer jelly coat, which is very loose, measures 6.4 to 10.4 milli- 
meters in diameter. 
The approximate time of egg deposition in California is indicated 
in one instance. On August 27, 1922, the writer found in Sonoma 
Creek opposite Agua Caliente a large mass of soft material which 
appeared very much like the remains of a Rana egg mass after the 
larvae had hatched out. Nearby in the creek were ‘schools’ of small 
ranid tadpoles measuring about 12 to 15 millimeters, a thousand or 
more in total number. These corresponded fairly well with the 
