29 o NEWTS AND SALAMANDERS. 



newts are very abundant in the western portion of this region, but as we 

 proceed eastwards they become less numerous, and we notice an approximation to 

 American types of the order, although only two genera are common to the Old and 

 New Worlds. North America is especially rich in Tailed Batrachians, containing 

 more than half the representatives of the entire suborder, and having the two- 

 legged salamanders (Sirenidce) peculiar to it. Axolotls are here especially abundant, 

 and there are also peculiar genera belonging to the families of the fish-like and 

 gilled salamanders. The Oriental region possesses only two species, namely, a 

 peculiar genus (Tylotriton) of newts in Yunan and the Eastern Himalaya, and 

 an axolotl in Siam. Tropical America, on the other hand, has ten species; 

 among which may be specially noticed the newts of the genus Spelerpes, 

 which are also represented by one species from Central America and the West 

 Indies, and two others from the mountains of Colombia, Ecuador, and Northern 

 Peru. Geologically, the group is by no means an old one, its earliest known 

 representative (Hylceobat rachus) occurring in the Wealden strata of Belgium ; and 

 these animals do not appear to have become abundant until the Tertiary epoch. 



Nearly all newts and salamanders appear to be inhabitants of water during at 

 least some period of their existence ; some frequenting muddy swamps, and others 

 deep lakes or subterranean waters, while a few are found in mountain-tarns at 

 elevations of several thousand feet above the sea. Without exception nocturnal in 

 their habits, spending the day in slumber either concealed in hiding-places on land, 

 or at the bottom of the water in their aquatic haunts, and venturing abroad only 

 at evening or after heavy rain, they are all difficult of observation, and consequently 

 much still remains to be learnt with regard to their mode of life. The terrestrial 

 species generally frequent soft, shady, damp spots, but occasionally narrow valleys 

 or forests where they conceal themselves under stones or fallen trunks of trees, or 

 in holes in the earth. During their permanent or temporary sojourn in the water, 

 the adults of those species unprovided with external gills are obliged to come 

 periodically to the surface in order to breathe ; and while in that element all are 

 less completely nocturnal than when on land. Such species as are inhabitants of 

 cold regions undergo a period of torpidity during the winter months ; while in 

 tropical regions others become quiescent when their haunts are dried up. They 

 exhibit a wonderful tenacity of life ; and when dried up in mud, or frozen in ice, 

 will awaken at the first shower of rain, or when their icy bonds are dissolved by 

 the sun's rays. They have also the capacity of reproducing lost limbs, apparently 

 any number of times. Although on land the majority of species are slow and 

 •sluggish in their movements, some salamanders from the south and west of Europe, 

 belonging to the genera Salamandrina and Chioglossa, run with the celerity of 

 lizards ; while others, again, climb sloping or perpendicular faces of rock, like 

 geckos. In the water all swim quickly, mainly by means of serpentine movements 

 of the tail ; although the water-newts are perhaps the most expert swimmers. All 

 are carnivorous in their diet, feeding chiefly upon molluscs, worms, spiders, and 

 insects. Their breeding-habits are peculiar in that there is usually no union 

 between the two sexes ; the females seizing the packets of spermatozoa deposited 

 by the males, and conveying them to their own reproductive chambers. While 

 some species lay eggs, in other cases the eggs are hatched within the bodies of the 



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