140 CHILDHOOD OF ANIMALS 



The young, too, occupying the same nest, swimming in the same 

 shoal and following the same guardian, acquire some power or 

 habit of association which, if it were conscious, we should call 

 recognition. 



Later on most fishes break away from the shoal and live strictly 

 individual lives, but there are not a few which continue to move 

 in masses throughout their lives, showing concerted action and a 

 feeble beginning of the social instinct. 



Most of the tailless batrachians, the frogs and toads, and 

 many of the tailed batrachians, the newts and salamanders, lay 

 a very large number of eggs, and exercise the least possible dis- 

 crimination in their selection of a spawning-ground. The common 

 British grass frog [Rana temporaria) breeds very early in spring, and, 

 no doubt attracted by the relative warmth of the water, chooses 

 the shallow edges of ponds, or temporary pools which may dry up 

 in a few days and leave the spawn stranded. The natterjack toad 

 {Bufo calamita) lives in sandy places, heath land, maritime dunes 

 and so forth, and deposits its masses of spawn in the nearest water 

 it can find, being content with the temporary rainpools in cart-ruts. 

 These toads are common on many of the Surrey heaths near London, 

 where they may breed from April until July, and only a very small 

 proportion of the eggs laid succeed in developing. The common 

 toad (Bufo vulgaris) limits its breeding, at least in England, to a 

 few weeks, from the middle of March to the end of April, according 

 to the season, and moves great distances to particular favoured 

 places, generally deep pools in quarries, where it deposits its eggs 

 in much more favourable conditions. Nearly all the tailless 

 batrachians live in or near the water, and the eggs, which are very 

 numerous, are deposited in water with no special precautions. In 

 a few, such as the spotted salamander, the eggs are retained in the 

 body of the female until they have actually hatched or are on the 

 point of hatching ; whilst some, such as Amphiuma and the 

 Coecilians, lay their eggs on land and protect them by coiling their 

 bodies round them. 



Amongst the tailless forms, however, brood-care may reach a 

 much higher level, with a consequent reduction in the number of 

 the young. Hyla faher, a Brazilian tree-frog, descends to the water 

 to breed, a male and female associating, but only the female pre- 

 paring the nursery for the young. She selects the shallow end of 

 a pool and dives to the bottom, bringing up loads of mud on her 

 head, which she gradually piles up to form the circular wall of a 



