70 INTRODUCTION. 



B. The forearms meeting on the pubic region 

 (Fig. 25, b) . . . • Pelodytes. 



II. Male holding the female behind or above the 

 arms. 



A. The hands dug into the axils or just above 



them (Fig. 26, a). 



B^ifo vulgaris, B. calamita, Hyla arborea. 



B. The hands pressed against the breast (Fig. 



26, b) , . . . Biifo viridis, Ra,na. 



Owing to the mode of embrace the fore limbs of 

 the males are always stronger than those of the other 

 sex, and in some species acquire about the breeding- 

 time a great muscular development. The inner side 

 of the inner finger may develop a thick pad, supported 

 l)y a corresponding development of the bones of the 

 rudimentary poUex and first functional finger, whicli, 

 pi'essed against the breast or pubic region of the female, 

 assists in maintaining the hold, often leaving a deep 

 scar if the pairing has been of prolonged duration. 

 There are developed in addition temporary horny 

 excrescences, in the form of small granules or spines, 

 which are present in most species, and afford useful 

 characters for their distinction during the breeding 

 season. When this is over the excrescences are shed 

 in most species. They, however, often persist through- 

 out the year in Biifo, Discoglossus, and Bomhinator. 

 These nuptial asperities are absent in Alytes and 

 I'elobates, and scarcely distinguishable in our Hyla. 

 When present, their shape and coloration, as well as 

 their distribution on various parts of the limbs or even 

 of the body, vary according to the species. With 

 regard to distribution, we find them located in fully 

 developed breeding individuals — 



On the inner side of the two inner fingers, the ante- 

 brachium, the brachium, the breast at the base 

 of the arm, the chin, the belly, and along the 

 toes_(Fig. 27, b) . . . Pelodytes. 



On the inner and upper side of the three inner 



