TOADS AND FROGS 



means of gills which absorb oxygen from the 

 water ; but as they get older these organs are 

 absorbed, lungs develop in their place, and the 

 tadpoles have to swim up to the surface and 

 get a supply of air whenever they feel in need 

 of it. To begin with, the tadpoles only eat 

 vegetable matter, but with increasing age they 

 develop a liking for something stronger, and 

 eat any animal matter they can find, including 

 each other when food gets scarce ! This is 

 sure to happen among those kept in a jar or 

 bowl imless they are well fed. A few bits of 

 meat dropped in will prevent such tragedies. 

 Many a tadpole falls a victim to its friends in 

 this way, and there are other ways in which 

 they come to an untimely end. There is the 

 grub of the great water beetle, which is a most 

 fearsome creature, being a perfect tiger among 

 the lesser things of the watery world. It has a 

 pair of strong jaws, and when once it has 

 grasped a tadpole in them it never lets go until 

 it has sucked its life juices dry. The water 

 beetle ^ is itself a danger, perhaps an even 

 greater one than its grub, for it too sucks the 

 life juices from tadpole after tadpole. Another 

 monster, which lies in waiting among the water 



' The great Water or Tiger Beetle, Dytiieut marginalis. 



109 



