BREEDING HABITS OF FROGS AND TOADS 



FEW phenomena in animated nature are more marvellous 

 than the development of ordinary frogs and toads, in the 

 course of which a creature to all intents and purposes a 

 vegetable-feeding fish becomes transformed into a carni- 

 vorous reptile. In all the ordinary frogs and toads of 

 Europe, Asia, and North America, the process of develop- 

 ment may, very briefly, be described as follows : The eggs, 

 which are enveloped in a glutinous matrix, are deposited 

 in large masses in water, and in due course develop into 

 the familiar tadpoles. At first the new-born tadpole affixes 

 itself to some convenient object by means of a sucker, but 

 in the course of a few days takes to a free-swimming mode 

 of existence. In its earliest days it breathes by means 

 of external gills, but these are soon replaced by internal 

 gills, covered by a gill-flap, and these again by lungs. 

 While these changes are going on, the hind-limbs, and 

 afterwards the fore-legs, bud forth from the body, the long 

 tail is absorbed, the larval mouth is replaced by the per- 

 manent one, and the coiled intestine is shortened and 

 straightened. And thus in due course the aquatic, gill- 

 breathing, limbless, long-tailed, herbivorous tadpole blossoms 

 forth as the terrestrial, lung-breathing, four-limbed, tailless, 

 and carnivorous frog or toad, as the case may be. 



If this state of things were common to all the members 

 of the group, it would be, as it is, sufficiently marvellous 



361 



