360 COMMON FROGS AND TOADS 



to escape notice whilst in their wonted environ- 

 ments. In many cases, indeed, the harmony is 

 so great, that the only thing about them that 

 may lead to detection is the persistently brilliant 

 yellow of their great, shining, goggle eyes. Even 

 as it is, their marvellous capacity for absolute 

 immobility often serves so effectually to conceal 

 them that their presence is only revealed when 

 they are almost underfoot, and go off with sudden 

 and huge leaps that are very startling to the nerves 

 of both men and dogs. The capacity for protective 

 change in colour in this instance, although not 

 acting so rapidly as it does in the case of wall- 

 geckos and many kinds of fish, is yet very 

 striking. 



Bull-frogs are excessively voracious, and many 

 well-authenticated instances are on record of their 

 successful capture of small birds, and even of palm- 

 squirrels, who have had the mishap to fall into 

 ponds haunted by them. Their fiercely carnivorous 

 tendencies manifest themselves very early. This 

 may be readily ascertained by putting some of 

 the small black tadpoles of the common toad, 

 Bufo melanostictus, into an aquarium containing 

 a few of their colossal grey relatives. At a time 

 when I was not fully informed in regard to their 

 habits, I tried keeping a mixed collection of both 

 kinds of tadpoles in a jar of distilled water, and 

 was astonished to find that the small ones rapidly 



