Reptiles and Birds / A Popular Account of Their Various Orders, With a Description of the Habits and Economy of the Most Interesting

by Louis Figuier

The Crested Newt, Triton cristatus, is frequently found in the neighbourhood of Paris; the skin of its back is rough and warty, of a brownish colour, with large black spots and white projecting points; the belly has black spots upon an orange ground.

The Dutch traveller, Sieboldt, has introduced a species of Aquatic Salamander, which inhabits the mountain lakes and marshes of Japan. This species is remarkable for its gigantic growth. Instead of being the size of a finger, as is the case with those indigenous to Europe, this Batrachian is four feet and a half in length, and weighs fifty pounds.

Magnificent specimens of this gigantic Salamander, the Sieboldtia maxima, may be seen by the visitors to the London Zoological Gardens. The largest of them measured and weighed as above (March 3rd, 1869). An analogous large fossil species was described as the Homo diluvii testis!

The transformation of the tailed Batrachians, from the tadpole condition to the air-breathing and four-footed state, is one of the most interesting exhibitions of Nature, and one which everyone may verify for himself. We cannot in our brief description have a more trustworthy guide than Professor Rymer Jones, who selects the Water Newt, Triton cristatus, as an example:—

"Immediately before leaving the egg," he says, "this tadpole presents both the outward form and internal structure of a fish. The flattened and vertical tail, fringed with a broad dorsal and oval fin; the shape of the body and gills, appended to the side of the neck, are all apparent; so that were the creature to preserve this form throughout its life the naturalist would scarcely hesitate in classing it with fishes, properly so called.

"When first hatched it presents the same fish-like body, and rows itself through the water by the lateral movement of the caudal fin. The only appearance of legs as yet visible consists in two minute tubercles, which seem to be sprouting out from the skin immediately behind the branchial tufts, and which are, in fact, the first buddings of anterior extremities. Nevertheless, to compensate to a certain extent for the total want of prehensile limbs, which afterwards become developed, two supernumerary organs are provisionally furnished in the shape of two minute claspers on each side of the mouth; by means of these the little creature holds on to the leaves which are under water.

"Twelve days after issuing from the egg, the two fore-legs, which at first resembled two little nipples, have become much elongated, and are divided at their extremity into two or three rudiments of fingers. The eyes, which were before scarcely visible, being covered by a membrane, distinctly appear. The branchiæ, at first simple, are divided into fringes, wherein red blood now circulates; the mouth has grown very large, and the whole body is so transparent as to reveal the position of the viscera within. Its activity is likewise much increased; it swims with rapidity, and darts upon minute aquatic insects, which it seizes and devours.

"About the twenty-second day the tadpole for the first time begins to emit air from the mouth, showing that the lungs have begun to be developed. The branchiæ are still large. The fingers upon the fore-legs are completely formed. The hind-legs begin to sprout beneath the skin, and the creature presents, in a transitory condition, the same external form as that which the Siren lacertina permanently exhibits.

"By the thirty-sixth day the young Salamander has arrived at the development of the Proteus anguinus; its hind-legs are nearly completed; its lungs have become half as long as the trunk of the body, and its branchiæ more complicated in structure.

"At about the forty-second day the tadpole begins to assume the form of an adult Newt. The body becomes shorter, the fringes of the branchiæ are rapidly obliterated, so that in five days they are reduced to simple prominences covered by the skin of the head; and the gills opening at the sides of the neck, which allowed the water to escape from the mouth as in fishes, and were, like them, covered with an operculum formed by a fold of the integument, are gradually closed; the membranous fin of the tail contracts, the skin becomes thicker and more deeply coloured, and the creature ultimately assumes the form and habits of the perfect Newt, no longer possessing branchiæ, but breathing air, and in every particular the Reptile."