AMPHIBIA. 229 



The " caducibranchiate " section of this order is charac- 

 terized by the fact that both pairs of limbs are always de- 

 veloped, and the branchiae are never retained throughout life. 

 The most familiar examples are the Water-salamanders or 

 Newts (Triton), and the Land-salamanders. The Newts (Fig. 

 113) are well known as inhabiting pools in many countries, 



FIG. 113. The great Water-Newt (Triton cristatm), male. (After Bell.) 



and the young lead a strictly aquatic life. When the lungs 

 are developed the external gills wholly disappear, and the 

 respiration becomes strictly aerial, though the animals still 

 spend a great part of their time in the water. The larva or 

 young form is at first destitute of limbs, and the fore-limbs are 

 the first to be developed, the reverse of this taking place in 

 the Frogs. In accordance with their mode of life, the tail is 

 compressed and flattened, so as to form an efficient swimming 

 apparatus. The Water-salamanders are all oviparous, and the 

 young are like the tadpoles of the common frog. 



The Land-salamanders, in both their adult and young 

 state, live upon land, and the tail is rounded and cylindrical. 

 The yeung are not developed in water, but are retained with- 

 in the body of the parent for a longer or shorter period, so 

 that the reproduction becomes ovo-viviparous, or even vivip- 

 arous. The best-known Salamanders occur upon the Con- 

 tinent of Europe, and one species is singular in the fact that 

 it inhabits high mountains. 



It is important to remember in connection with all these 

 " tailed " Amphibians, that they are wholly distinct from the 

 true Lizards, with which they are often confounded. Many 

 of them are completely lizard-like in form, having a long tail 

 and two pairs of legs ; all, however, at some time or other in 

 their life, respire by means of gills, and this is never the case 

 with any true Lizard. It must be confessed, however, that a 



