280 



FROGS, TOADS, AND NEWTS 



[CH. VIII 



Fig 48. 



A.. The left manus of Eana 

 temporaria. Palmar 

 surface. 



B. The same of the ? . 



smaller size and less cumbrous figure, the body of the 

 female being greatly distended by the ripe ova and 

 enlarged oviducts. Moreover the coloration now differs 

 in the two sexes. The dorsal 

 surface of the male becomes a 

 uniform dark olive-brown colour, 

 and the temporal blotch almost 

 ceases to be distinguishable : the 

 ventral surface, and especially the 

 throat, becomes extraordinarily 

 pale and is a faintly bluish grey 

 colour. On the other hand, the 

 pigments of the female are sharply 

 contrasted ; the general colour is a 

 yellowish brown relieved by small spots of bright yellow : 

 the temporal blotch is more than usually conspicuous and 

 the ventral side of the body, particularly the throat, is 

 coloured as warmly as the flanks and dorsal surface. In 

 both sexes a cresentic mark of golden yellow appears upon 

 the skin bordering the nasal margin of the eye-ball. The 

 innermost (true 2nd) digit also of the male is at this season 

 modified for mating purposes. This digit is normally 

 somewhat swollen at the base but during the breeding 

 season the swelling enlarges and becomes of a black-brown 

 colour; the epidermis covering it becomes thickened and 

 papillous. The enlargement is chiefly caused by the in- 

 crease in size of the mucous glands of the skin in this 

 region. The papillaB are peculiarly rich in " touch- spots " 

 nerve structures which also occur on the dorsal surface 

 of the trunk and under-surface of the hind feet. 



