Frogs and Toads 



gravel beds of some clear water stream. At the other 

 extreme are the elaborate nests of the sticklebacks. 



Two rather curious facts strike the naturalist bent on 

 studying the nesting habits of fishes : the fresh-water 

 fishes are far better architects and builders than their 

 sea-water relatives and it is almost invariably the male 

 who acts as nurse. An exception to the latter rule is 

 afforded by the British butter-fish, a somewhat eel-like 

 creature, who rolls her eggs into a ball by coiling her 

 body round them ; the male and female, in turn, guard 

 the egg mass in this manner. After a while, apparently 

 tiring of their cares, the fishes remove their eggs from the 

 sandy beds where they have lain and deposit them, in 

 clumps, in the holes made by the piddock, a common 

 shell-fish of our coasts whose activities are discussed in 

 another chapter. 



The little gobies, sand-coloured denizens of marine 

 pools, go a step further in their ideas of house-building. 

 They select a shell that of the limpet is often chosen, or 

 even the hard covering of a crab and turn it so that the 

 hollow of whatever building material they have decided 

 upon is at the lower side ; in other words, they make a 

 tent of their borrowed home. From beneath this shelter 

 they hollow out the sand and proceed to make a circular 

 opening at one side. This circular opening is their front 

 door, but, being made of sand, it is liable to collapse at 

 any minute. The father goby, however, is equal to the 

 occasion ; he swims to and fro, in and out of his front door, 

 rubbing his scaly sides on his structure as he does so. 

 One might think that this performance on the part of the 

 male fish was something in the nature of an exhibition of 

 delight at having a home of his own ; in reality he is 

 covering the sand around the door with a slimy secretion 

 from his body. This secretion holds the sand particles 

 together. 



The nest completed, eggs are laid on the inner side of 

 the roof of the shelter. The male, it must be admitted 



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