94 



Batraciiiaxs.- 



-REPTILES.- 



-Batrachians. 



Only Olio species of this family is found in Europe — 

 THE COMMON TEEE-FEOG [Hyla arhorca) is a 

 pretty aiul interesting little creature, and one of the 

 smallest of the Eurojiean Tailless Batrachians. It is 

 very common in the southern, and indeed in most of 

 the countries of Illurope, Groat Britain excepted ; and 

 is also fonnd in North Africa, Asia Minor, China, and 

 Japan. It has a short, thick head, large projecting 

 eyes, a thick, round tongue, a short body of a some- 

 what triangular figure, and a smooth skin, except 

 under the throat, chest, and belly. The binder 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, 

 e.xcept 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 

 sidi'S 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 assimied 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 I!oesel 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 c^f the trees, that the Tree-frog passes the 

 greater portion of the summer. So adhesive are tlie 

 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 by. 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 {Miis- 

 cicapa grisoln), which takes gnats and flies much in 

 the same raanrjcr, by an abrupt attack on such as pass 

 near its perch of observation. But the Tree-fiog does 

 more ; it lurks under the leaves of the highest branches, 

 and seizes such unwary molhs or flies as settle within 

 the reach of its tongue, w'liich 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 reproduction 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, mimbers 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 tlie 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. They 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 Jlaga- 

 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 arhorca 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 cat 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 lai'ge 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 GRYLLUS 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. IIol- 

 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, wdiich 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 savaimas 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 



