264 



AMPHIBIANS, 



As regards their general distribution, Amphibians closely resemble fresh-water 

 fish, and differ widely from lizards. Indeed, from an Amphibian point of view, 

 the globe may be divided into two great regions, namely, a northern one 

 characterised by the abundance of newts and salamanders, and the absence of 

 caecilians ; and a southern one distinguished by the want of the former and the 

 presence of the latter group. 



In their mode of life, it is probable that very few Amphibians 

 are diurnal ; most of the terrestrial forms making their appearance 

 abroad with the first shades of evening, and retiring to their hiding-places at 

 dawn. In wet or cloudy weather frogs and toads — especially in South America — 

 frequently appear in great numbers during the day ; and both these groups are 



Habits. 



moor-frogs (nat. size). 



in the habit of making night hideous with their croakings. Although in all cases 

 the adults are carnivorous, the larvae subsist more or less exclusively on vegetable 

 substances; some confining themselves to that kind of diet, while others also 

 consume animalcules and other minute creatures. 



Characteristics of The f rogs and toads are distinguished from their allies by the 

 Frogs and Toads, presence of four limbs and the absence of a tail in the adult state ; 

 the latter feature giving origin to the name Ecaudata, by which the order to 

 which they belong is scientifically designated. They all have short and frequently 

 thick bodies, in which the backbone comprises, at most, only eight vertebrae in 

 advance of the sacrum ; those behind the latter being fused into a long rod-like 

 bone, as shown in the figure of the skeleton on p. 261. In the fore-limb, as shown 

 in the same figure, the bones of the fore-arm (radius and ulna) are completely fused 

 together ; and the same is the case with regard to the tibia and fibula in the hind- 



