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LAKES AND STREAMS 



Moor-Frog. 



Among the more typical frogs of central Europe, the moor-frog 

 ( Rana arvalis) maybe classed as one of the water-dwellers, and may 

 be distinguished from the agile frog by the shortness of its hind-legs. It attains 

 a length of about 2 inches, and is not often found west of the Rhine; its area 

 extending into Siberia to the east, up to the Arc-tie Circle in the north, and in the 

 south including Alsace, Hungary, Asia Minor, the Caucasus, and northern Persia. 

 Inhabiting only the lowlands and broad river-valleys within the area of its dis- 

 tribution, this frog is most numerous on the northern European plain and its 

 Siberian continuation, as are also the fire-bellied frog and garlic-toad. The moor- 

 frog's favourite haunt is among marshy places, interspersed with ditches and 

 pools: the common frog sharing, in a similar way to the viviparous lizard and 

 the sand-lizard, the territory it inhabits. It seems, however, that the males, 



EDIBLE FROG. 



Edible Frog. 



which are provided with larger webs on their feet than the females, are more at 

 home in the water, and it is possible that only males are found in water during the 

 winter-sleep, which lasts Erom November to February or March. 



The edible frog ( R. i-sculciitu), which is more decidedly aquatic 

 than the last, is easily distinguishable from the other central 

 European species by its greenish back, the mottled black and yellow back of the 

 hind-leg. and the large webs which extend as far as the tips of the toes. There 

 are several varieties of the species, two of which, the pond and the lake race, are 

 found in central Europe. The lake form is larger and heavier than the other, and 

 its coloration less vivid and more uniform, the upper-parts not being of such a 

 decided green, but more olive-brown, marked with greyish black or bronze-brown 

 spots. The lake race attains a length of 4.1 inches, and is differently distributed 

 to the pond form. It inhabits deep, broad streams and river-valleys in central and 



