The skull of the Land or Spotted Salamander, Salamandra maculosa, is well described by Cuvier as being nearly cylindrical, wider in front so as to form the semi-circular face, and also behind for the crucial branches, containing the internal ears. The cranium of the aquatic Salamander differs from the terrestrial in having the entire head more oblong, and they differ also among themselves.
Fig. 9.—Land Salamander.
In the Land Salamander the body is black and warty with large irregular yellow spots distributed over the head, back, sides, feet, and tail. They affect obscure and moist places, and only issue from their retreat in the night or morning, walking slowly, and dragging themselves with difficulty along the surface of the ground. They live upon flies, beetles, snails, and earth worms. They remain in the water to deposit their eggs; the young are born alive, and furnished with fully-developed gills. Moreover Salamanders are gifted with a power which causes them to be much dreaded by other animals: it has the power of discharging an acrid and milky humour, with a very strong odour, from the surface of its body, which serves as a defence against many animals which would otherwise attack it. It has been proved by experiment that this liquid, when introduced into the circulatory system by a small wound is a very active poison, and causes certain death to the smaller animals. This species is found in most parts of Europe, but not in the British Islands.
The Black Salamander, Triton alpestris, has no spots; it is found on the highest European mountains, in the regions of snow, and principally on the highest Alps.
Fig. 10.—Newts, or Aquatic Salamanders.
Newts, or Aquatic Salamanders, have not a round conical tail like the terrestrial species, but have that appendage compressed or flattened laterally. The males (during the breeding season only) are recognised chiefly by the membranous serrated ridge or crest which extends along the whole length of the back, from the head to the extremity of the tail, as represented in [Fig. 10]. Newts are highly aquatic; they are found in ditches, marshes, and ponds, which after the breeding season they leave for moist places on land, often then finding their way into drains and cellars. They are carnivorous, feeding upon different insects and on the spawn of Frogs, not even sparing individuals of their own species. The females deposit their eggs singly, fixing them on the under surface of the leaves of aquatic plants. "Some Newts," says Professor Owen, "deposit their eggs upon aquatic plants, such as Polygonum persicaria, folding the leaf by means of the hind feet in such a way that its under surface is turned inwards and the fold made to stick by the adhesive coating of the egg, which she inserts in the fold." The young are hatched fifteen days after. These animals give utterance to a very peculiar noise, and when touched emit an odour quite characteristic.
It has been ascertained that Newts can live for a long time, not only in very cold water, but even in the midst of ice, being sometimes taken in blocks of ice which are formed in the ditches and ponds which they inhabit. When the ice-flakes melt they seem to awaken from their torpor, and betake themselves to their accustomed movements with their recovered liberty. Lacépède states that he found Aquatic Salamanders even during summer in pieces of ice obtained from the ice-dealers, where they had remained without movement or nourishment from the time when the ice had been gathered from the marshes.
Newts present another remarkable feature in the facility with which they repair any mutilations they may have undergone. Not only do their tails grow again when broken off, but even their feet are reproduced in the same manner, and the process may be many times repeated.