CHAPTER IV 



REPRODUCTION 



Tail-less Batrachia, general course of development. Various modes of pro- 

 tecting the eggs : nests in the water and on land. Eggs carried by the parents, 

 round the legs by the male, on the skin or in a dorsal pouch by the female, in 

 enlarged vocal sacs by the male. Pairing in Urodela. Protection of eggs by 

 Urodeles. Salamanders that carry their eggs. Viviparous salamanders. 



IN frogs and toads, such as occur in temperate climates, 

 pairing and oviposition generally take place in the 

 water, whether the species, outside the breeding season, 

 be terrestrial, burrowing, or aquatic. The male catches hold of 

 the female, either under the arms or round the waist, and 

 awaits, in an embrace that may last days or even weeks, the 

 extrusion of the eggs, which, as he sits on her back, he impreg- 

 nates by successive emissions of the fertilising elements. 



This function over, the pair separate and the eggs are 

 abandoned to their fate, either floating in large masses on the 

 surface, or attached singly or in bunches to submerged objects, 

 or forming strings twined round reeds or other aquatic plants. 

 In most of our northern species, there is a fixed annual period 

 of reproduction, taking place at the end of winter or in spring ; 

 but there are exceptions : in the family Discoglossidae, for 

 instance, members of which breed several times during the 

 spring and summer, at distant intervals ; and between these 

 two extreme types, almost every possible gradation intervenes. 



Species differ greatly in the choice of a site for depositing 

 their ova, some showing a remarkable discrimination whilst 

 others spawn in ditches or puddles of a most temporary nature 

 (although suitable places may be easily accessible to them) the 

 drying up of which may result in a wholesale destruction of the 

 progeny. But nature has provided for such a waste, the frogs 

 which so behave being at the same time the most prolific. 



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