362 



ZOOLOGY 



Photograph by E. R. Sanborn, N. Y. Zotil. Soc. 

 FIG. 141. African swimming frog. 



toads, called the Aglossa, is without a tongue. 

 The tongue of the frog is a remarkable struc- 

 ture, attached in front instead of behind, and 

 capable of being thrust out with great rapidity 

 to take an insect. Some toads have very 

 poisonous secretions. Gadow calls attention 

 to the brilliant red under surface of the fire- 

 bellied toad of Germany, and shows that this 

 serves as " warning coloration." He states that 

 the secretion of the skin is very poisonous, and 

 he knows of no creature which will eat or even 

 harm them. He kept large numbers in a viva- 

 rium, together with various snakes, tortoises, 

 and crocodiles ; but for years they remained 

 unmolested, although they shared a pond in 

 which no other frog or newt could survive. 

 Hungry water tortoises would stalk them, and 

 touch them with the nose to get the scent, 



