176 THE HAUNTS OF LIFE 



frogs in March or April, then look for the 

 clumps of jelly-like eggs, take them home and 

 keep them in a properly shaded vessel, and we 

 can follow the whole fascinating story. But we 

 must be careful to keep water-plants growing 

 in our aquarium, that the water may be aerated, 

 to supply food, but to remove all decaying 

 matter, and to provide a foothold for the little 

 creatures when they are about to make their 

 great change from the tadpole to the frog stage. 



All the members of the group have in their 

 full-grown state the great characteristic of 

 adult terrestrial animals they breathe, by 

 means of lungs, the oxygen in the air. But the 

 young of almost all of them have gills 

 and breathe the oxygen dissolved in water. 

 The time the tadpole breathes by gills may 

 be longer in one family than another, it may 

 even vary in the same family, according to 

 surroundings and weather, but, long or short, 

 it is very rarely omitted. 



Another fact that shows the direction in 

 which they are tending is that even the adults 

 are not all equally terrestrial in habit. Both 

 frogs and toads spend some time in the water 

 in spring, and leave it when their eggs are 

 safely deposited. But as winter approaches, 



