THE YOUNG NATUEALIST. 



191 



to the shoulder, which is always present in Rana temporaries ; secondly, the 

 presence of a well-marked dorsal line. Though the edible frog is usually 

 larger than the common one, and generally of a bright pea-green colour, yet 

 these are not alsolutely distinctive characteristics. 



I never had the pleasure of seeing this handsome species in its native 

 haunts. I am indebted for the specimens on which my observations have 

 been based, to the kindness of Mr. B. Corcoran, of London, who pro- 

 cured them from a friend in Paris. They arrived from Paris on the 

 1st June, 1887, having stood their long journey well; they were evidently 

 not quite ready for breeding, as the males had not yet developed their suckers, 

 and had not begun to croak. On the 5th June, my wife was startled by an 

 unusual sound, coming from the room in which these creatures were. I 

 guessed the cause, and found the males indulging in their love song, whose 

 remarkable power, so much louder than that of the common frog, is owing 

 to the vocal sacs, situated one at either side of the mouth, and which, during 

 the emission of the sound are distended to the size of a cherry, and are of a 

 milk white colour. The distention is only temporary, ceasing with the sound. 

 The appearance of the head, whilst the sacs are distended, is very curious. 

 As in the common frog, the males only croak during the breeding season. 



On the 13th June, the males had developed suckers, and the frogs paired 

 as in the other species already described. The spawn was deposited on the 

 20th of June. The eggs were smaller than those of the common frog, being 

 only f\in. diameter ; and the embryos are of a lighter colour than those of 

 Rana temporaria. 



On the 24th June, the young tadpoles appeared, and five days later lost 

 their external gills. The young tadpoles are quite green when hatched, but 

 on the 3rd day change to a darker marbled green ; unlike the common tad- 

 pole, the posterior half of the ventral surface is of pale yellow. Knowing 

 from experience the unreliability of statistics of development obtained under 

 artificial conditions, I cannot venture to give the periods for the development 

 of the legs, not having had any opportunities of observing them in a state of 

 nature. Those I had in captivity were as slow, if not slower, than the tad- 

 poles of Rana temporaria ; and therefore I conclude that the growth of the 

 young Esculenta is on parallel lines. 



The cutaneous respiration described at length under Rana temporaria, is 

 as important and as effective in this species ; and it is unnecessary to do 

 more than refer to it here. 



In this species the ground colour is generally pea green, though some 

 specimens are dark brown, and others again of various intermediate shades. 

 The markings are black spots irregularly distributed over the dorsal surface. 



