94 Batrachians. REPTILES. Batrachians. 
Only one species of this family is found in Europe — 
THE COMMON TREE-FROG {Hyla arhorea) is a 
pretty and interesting little creature, and one of the 
smallest of the European Tailless Batrachians. It is 
very common in the southern, and indeed in most of 
the countries of Europe, Great Britain excepted ; and 
is also found in North Africa, Asia Minor, China, and 
Japan. It has a short, thick head, large projecting 
e 3 'es, a thick, round tongue, a short body of a some- 
what triangular figure, and a smooth skin, except 
under the throat, chest, and bellj\ The hinder limbs 
are of considerable length, and the fingers and toes 
are partially webbed. The general colour on the 
upper parts of the body is a fine, delicate green, 
except on the fingers and toes, which present a slight 
rosy hue, whilst the under surface is white. A yellow 
stripe bordered with pale violet stretches along the 
sides of the head and body, and down the hind legs to 
the feet, while a similar stripe branches off and extends 
down the arms to the fore feet. After the breeding 
season, however, the animal becomes of a reddish- 
brown, which soon changes to gray, mottled with 
spots of a reddish hue. The colour next assumed is 
one passing into blue, and in spring this changes again 
to its proper livery, green. The males are always 
larger than the females, and possess large vocal sacs 
under the throat. These, when swollen up, resemble 
a protuberance as large as the whole head, which at 
such times appears like a large globular bladder. Its 
chief food consists of insects, and, as Roesel remarks, 
its stratagems for securing its prey resemble very much 
those of the bat as it watches a bird or a mouse. “ It 
is in the midst of the woods, among the foliage and 
branches of the trees, that the Tree-frog passes the 
greater portion of the summer. So adhesive are the 
glutinous cushions of its toes, that, however smooth 
and polished the surfaces may be on which it rests, 
they affix themselves intimately to them ; nay, it mat- 
ters not whether the creature adhere to the under or 
upper surface of a leaf ; in either place it is alike 
secure. All the summer long, in the warm and sunny 
regions of the South, may this little animal be watched 
among the leafy woods, engaged in the pursuit of various 
insects, darting after them as they pass within the dis- 
tance of its spring. It seizes them with its glutinous 
tongue, and rapidly draws them into its mouth ; and 
having swallowed one insect, it darts at the next that 
flits bj'. This restless activity, this unceasing repeti- 
tion of leaps, not unlike the short, darting flights of a 
bird, from leaf to leaf, or from bough to bough, have 
induced some to compare it to the Fly-catcher [Mus- 
cicapa grisola), which takes gnats and flies much in 
the same manner, by an abrupt attack on such as pass 
near its perch of observation. But the Tree-frog does 
more ; it lurks under the leaves of the highest branches, 
and seizes such unwaiy moths or flies as settle within 
tlie reach of its tongue, which it can launch out to a 
considerable distance.” — Martin. The alertness and 
agility which this little frog displays, are truly astonish- 
ing. It is able to leap a distance of many feet, and 
though Catesby’s assertion that it leaps to a distance 
of twelve feet at a single bound may be exaggerated, 
yet the leaps which it does take are surprising, not 
only from their extent, but from their address and 
precision. As the season for reiuoduction advances, 
the Tree-frogs leave their abode upon the trees and 
take to the water. The union of the sexes takes place 
in the end of April, or not till the beginning of June, 
according to the temperature of the season. At that 
period the males croak very loudly, and when, as is 
usually the case, numbers are collected together, the 
clamour caused by them is so great, that at a distance 
it might be taken for the cry of a pack of hounds in 
full chase ; and when the wind blows gently in the 
right direction, it may be heard at the distance of more 
than a league. When this season is over, they again 
seek their favourite haunts amongst the foliage of the 
trees, where they remain till the autumn sets in ; and 
then, warned by the cold, they begin to prepare for 
their winter repose. Thej^ withdraw themselves to the 
water, and, plunging to the bottom, bury themselves 
there in the soft mud, where they tranquilly sink into 
a state of torpor, in which they remain till spring 
returns. From their agreeable colours and sprightli- 
ness, the Tree-frogs are sometimes kept as pets. “ At 
Schwetzingen,” says the late Mr. Loudon in his Maga- 
zine, “ in the post-house we witnessed for the first 
time what we have since seen frequently, an amusing 
application of zoological knowledge for the purpose of 
prognosticating the weather. Two frogs of the species 
called Rana arbwea are kept in a crystal jar, about 
eighteen inches high and six inches in diameter, with a 
depth of three or four inches of water at the bottom, and 
a small ladder reaching to the top of the jar. On the 
approach of dry weather the frogs mount the ladder ; 
but when moisture is expected, they descend into the 
water. In the jar they get no other food than now 
and then a fly, one of which we were assured would 
serve a frog for a week, though it will eat from six to 
twelve in a day if it can get them.” 
A great many species of Tree-frogs are natives of 
the New World. In most of them, as well as in the 
species already mentioned, the discs at the extremities 
of the toes are large and well developed ; but there are 
some of the Hylina in which these organs are very 
small, while the toes themselves are broadly webbed. 
THE ACRIS GRYLIUS is an example of this group. 
This little Tree-frog is commonly known in the 
United States of America by the name of the Savan- 
na Cricket. It is only one and a half inch in length, 
is very common in Carolina and Georgia, and is found 
extending from lat. 43° north to the Gulf of Mexico. 
The body is slender and elongated, of a dusky colour 
above, with a vertebral line of bright green or reddish- 
brown, and of a silvery white beneath. As Mr. Hol- 
brook says, this is a merry little frog, constantly chirp- 
ing like a cricket, even in confinement. Bartram met 
with these little creatures in his travels, and thus de- 
scribes them ; — “ There is yet an extreme diminutive 
species of frogs, which inhabits the grassy verges of 
ponds in savannas; these are called Savanna Crickets, 
are of a dark ash or dusky colour, and have a very 
picked nose. At the time of very great rains, in the 
autumn, when the savannas are in a manner inundated, 
they are to be seen in incredible multitudes, climbing 
up the tall grass, weed, &c., around the verges of the 
