DISC-TONGUED FROGS. 



285 



Midwife-Frogs. 



they develop black rugosities on the inner side of the fore-arm, as well as on the 

 inner tubercle of the metacarpus, and on the two innermost front-toes. There are 

 two varieties of this frog (reckoned by some as distinct species), of which the one 

 with orange-coloured under-parts is to be found in streams or marshes in the 

 lowlands, while the yellow-bellied form lives at considerable elevations in the 

 mountains. They are essentially aquatic frogs, only leaving the water for a short 

 time in the spring, when they may be seen hopping on the land on their long 

 hind-legs. In the water they generally take up their position at some distance 

 from the bank, sitting with their heads slightly raised above the surface, and dis- 

 appearing with lightning-like speed at the slightest noise, to seek safety in the 

 mud at the bottom. The tadpoles grow to an unusually large size, and are 

 especially characterised by the great development of the tail-fin. 



The third European representative of the family is the so-called 

 midwife-frog (Alytes obstetricans), of which the typical form inhabits 

 France, Switzerland, Belgium, and Western Germany, while a variety occurs in 

 Spain and Portugal ; 

 Spain being also the 

 home of the second 

 member of the genus (A. 

 cisternasii). From the 

 fire-bellied frog these two 

 species are distinguished 

 by the distinct external 

 tympanic membrane to 

 the ear, the elliptical and 

 vertical pupil of the eye, 

 and the moderate ex- 

 pansion of the transverse 

 processes of the sacral 

 vertebra. The common 

 species has the skin of 

 the upper - parts warty, 

 while that of the under 

 surface is granular; the 



glands near the head are small or indistinct, but there are large ones on the limbs ; 

 and the males have no vocal sac. The colour of the upper-parts is olive-grey, with 

 darker dots and irregular spots. Essentially an aquatic species, this frog derives 

 its name from the circumstance that the male takes charge of the eggs during 

 their development. The breeding-season lasts for upwards of six months, namely, 

 from March to August, although the eggs are laid only from March till June. 

 These are deposited by the female in the form of long chains, which may be 

 upwards of a yard and a half in length. These chains are taken by the male, and 

 wound round his legs and thighs ; and when thus loaded he retires to some burrow 

 or convenient hollow near the bank, where, at least during the daytime, he remains 

 in concealment until the tadpoles are ready for hatching. He then enters the 

 water, and the tadpoles soon come forth, and swim away to take care of them- 



MALE OF MIDWIFE-FROG WITH CHAINS OF EGGS (nat. size). 



