Indigenous to Southern Europe.
The Horned Frogs, or Horned Toads, of South America constitute a distinct and interesting group. They are of large size, stout and rotund, gorgeously apparelled, and truculent in bearing. There are nearly a dozen known species, the distinctive feature from which they take their name having reference to the stiff, horn-like development of their upper eyelids. The largest species is a native of Brazil, whose body may be as much as 8 inches long. This species has the horn-like processes of the eyelids most prominently developed. A somewhat smaller but conspicuously handsome species, plentiful in the Argentine Republic, is at the present time represented by several individuals at the Regent's Park Gardens. In this animal the body is relatively more obese and toad-like than in the Brazilian form, but the horn-like angle of the upper eyelid is only slightly produced. The colours vary somewhat, the general ground-tint of the upper-surface is bronze-green or yellow, upon which are distributed large spots and blotches of dark olive or chocolate, having light yellow or golden margins. The spots on the limbs are the widest, and almost take the character of cross-bands. Bright claret-red lines are sometimes developed in and among the body-spots.
A very interesting account of the habits of this frog appears in Mr. W. H. Hudson's "The Naturalist in La Plata." Mr. Hudson reports it as being common on the pampas as far south as the Rio Colorado, in Patagonia. In the breeding-season it congregates in pools, and displays extraordinary vocal powers, which are exercised at night. The notes uttered are long, resembling those of a wind instrument, and are so powerful that on still evenings they may be heard distinctly a mile off. After the pairing-season the frogs disperse, and, retiring to moist places, bury themselves just deep enough to leave their broad green backs on a level with the surface. The eyes, under these conditions, look out as from a couple of watch-towers, and are on the qui vive for any approaching prey. This consists of any moving creature which they can capture, such as other frogs and toads, birds, and small mammals. In very wet seasons they will frequent the neighbourhood of houses, and lie in wait for chickens and ducklings, often capturing and attempting to swallow objects much too large for them. In disposition they are exceedingly pugnacious, savagely biting at anything that comes near them. When teased, the creature swells itself out to such an extent that one expects to see it burst. It follows its tormentors about with slow, awkward leaps, its vast mouth wide open, and uttering an incessant harsh croaking sound. When they bite, these frogs hold on with the tenacity of a bull-dog, poisoning the blood of the creature seized with their glandular secretion. Mr. Hudson records two instances in which to his knowledge horses were killed through being bitten by a horned frog. One of them, while lying down, had been seized by a fold in the skin near the belly; the other had been grasped by the nose while cropping grass. In both instances the vicious frog was found dead, with jaws tightly closed, still hanging to the dead horse. "It would seem," Mr. Hudson remarks, "that they are sometimes incapable of letting go at will, and, like honey-bees, destroy themselves in these savage attacks."
The Tree-frogs represent one of the most distinct groups of the tribe. All its members are more or less arboreal in their habits, repairing to the water only during the breeding-season, or leaving the trees to seek shelter in the earth or underneath stones or timber for the purposes of hibernation. As an adaptation for their special habits, the toes of the tree-frogs are provided at their tips with suctorial disks, so that they can walk on perpendicular or smoothly glazed surfaces after the manner of the Geckos among the Lizards. Another characteristic feature is the development on the under surface of their bodies of peculiar granular glands pierced by numerous pores, through the medium of which they rapidly absorb the moisture deposited by dew or rain on the surfaces of the leaves among which they live. The colours of the tree-frogs harmonise, as a rule, so completely with those of their leafy environments that their presence very readily escapes detection. Many of the species, moreover, rival the chamæleon in their capacity of quickly adapting their tints to that of a newly occupied surrounding. Green is naturally the dominant ground-tint of these frogs. Often, however, it is intermixed with stripes and bands of other colours, while sometimes the green hue is entirely replaced, as in the Blue or Bicoloured Tree-frog of South America, which is brilliant azure above and pure white beneath. A very beautiful Australian species, abundant in Tasmania and Victoria, and appropriately named the Golden Tree-frog, has its grass-green overcoat thickly overlaid and embroidered with, as it were, the purest beaten gold.
Photo by W. Saville-Kent, F.Z.S., Milford-on-Sea.
QUEENSLAND TREE-FROGS.
This species is in the habit of making itself at home in chamber water-jugs.
Photo by H. G. F. Spurrell, Esq.] [Eastbourne.