312 THE FROG. 



slow growth with their other habitudes, it would appear 

 that they live about twelve years ; but .having so many 

 enemies, both by land and water, it is probable that few 

 of them arrive at the end of their term. 



Frogs live upon insects of all kinds ; but they never eat 

 any unless they have motion. They continue fixed and 

 immoveable till their prey appears ; and just when it 

 comes sufficiently near, they jump forward with great 

 agility, dart out their tongues, and seize it with certainty. 

 The tongue, in this animal, as in the toad, lizard, arid 

 serpent kinds, is extremely long, and formed in such a 

 manner, that it swallows the point down its throat ; so that 

 a length of tongue is thus drawn out, like a sword from its 

 scabbard, to assail its prey. This tongue is furnished 

 with a glutinous substance ; and whatever insect it touches, 

 infallibly adheres, and is thus held fast till it is drawn into 

 the mouth. 



As the Frog is thus supplied with the power of catching 

 its prey, it is also very vivacious, and able to bear hunger 

 for a very long time. I have known one of them continue 

 a month in summer without any other food than the turf on 

 which it was placed in a glass vessel. We are told of a 

 German surgeon, that kept one eight years in a glass ves- 

 sel, covered with a net. Its food was at all times but 

 sparing ; in summer he gave it fresh grass, which it is said 

 to have fed upon ; and, in the winter, hay, a little moist- 

 ened : he likewise, now and then, put flies into the glass 

 which it would follow with an open mouth, and was very 

 expert in catching them. In winter, when the flies were 

 difficult to be found, it usually fell away, and grew very 

 lean ; but in the summer, when they were plenty, it soon 

 grew fat again. It was kept m a warm room., and was 

 always lively and ready to take its prey : however, in the 

 eighth winter, when there were no flies to be found, it fell 

 away and died. It is not certain how long it might have 

 lived, had it been supplied with proper nourishment ; but 



