310 ‘ THE VIVARIUM. 
common Frog swimming near him is sure to be engulfed without 
much difficulty ; and if a mouse be dropped out of a trap within 
comfortable reach, it will be almost certain to follow the unfortu- 
nate Batrachian ; the tail of the rodent may be left for a moment 
or two outside the huge jaws, only to be presently pushed out of 
sight by the skilful use of the gourmand’s fore-feet, or rather 
hands, as they should be called. 
Besides frogs and mice, &. catesbiana will eat lob-worms, 
—sparrows, fish, tadpoles, and newts. Worms I find to be the 
most convenient to provide. 
Though the Bull Frog, when full grown, is so large, its tadpole 
is extremely small by comparison. According to Cassell’s 
“Natural History,” ‘‘the mature animal measures from 13in. to 
21m. in length, limbs included. The prices of American Bull 
| Frogs in this country range from 5s. 6d. to 15s. 
Of R. catesbiana the tympanum is generally much larger than 
the eye, particularly in the case of the male; the eye, having a 
golden iris, is large and very beautiful ; the fingers are pointed, 
and the toes are fully webbed. The colour above is generally 
lightish green or dusky olive marbled with similar colours, but of 
a darker shade. The lower parts are yellowish-white, sometimes 
slightly marbled. |The male has two internal vocal sacs. The 
late Mr. Frank Buckland, speaking of this Frog’s power of 
making a noise, says, in his ‘‘ Curiosities of Natural History,” 
“Tn the Bull Frog we find a very peculiar piece of mechanism, by 
means of which the animal is enabled to produce the well-known 
bellowing sound described by travellers ; hence his name — Bull 
Frog. Certain portions of the larynx (the arytenoid cartilages) 
are convex externally, and concave internally, so that when the 
entrance to the larynx is closed, they form a dome over the wind- 
pipe, —which Cuvier has compared to a drum.” 
The American Bull Frog may be kept in the same manner as 
has been suggested for his Indian relative (2. tigrina). The two 
Batrachians will live very well in the same Vivarium, if both be of 
about the like size. 
The Noisy Frog (R. clamata) is well named. It is now fairly 
frequently imported into this country, and may be purchased at 
abcut the same prices as those quoted for the sale of R. cates- 
