CHAPTER XVII 



THE AMPHIBIA 



" Sweet are the uses of adversity ; 

 Which, like the toad, ugly and venomous, 

 Wears yet a precious jewel in his head." 



" UGLY and venomous," I am afraid, is still as much the popular 

 idea of those animals the frogs, toads, newts, and salamanders 

 included in the Amphibia as it was in Shakespeare's day. By 

 most people they are still looked upon as " horrid, slimy things/' 

 if not as actually dangerous animals, capable of spitting fire and 

 poison. Yet the majority are comparatively harmless and, 

 indeed, most useful animals, and the tongue of the frog and the 

 toad is indeed a precious weapon, capturing with unerring aim 

 countless slugs and caterpillars that would eagerly devour the 

 tender foliage of growing plants. In fact, they are really a most 

 deeply interesting group of animals. 



The Amphibia have sprung from fish-like ancestors, and in 

 turn have given rise to the Reptilia. Consequently, they occupy 

 a very important intermediate position between the fishes on 

 the one hand, and the higher air-breathing vertebrates (reptiles, 

 birds, and mammals) on the other. They differ from all fishes in 

 the entire absence of fin-rays, and from all fishes except the Dipnoi 

 (lung-fish) in the presence of lungs in the adult for breathing 

 air. In the majority of the Amphibia the larval gills become 

 absorbed ere maturity is reached, but in some are retained through- 

 out life, the animal breathing by means of both lungs and gills, 

 after the manner of the Dipnoi. The general shape of the Amphibia 

 indicates their more or less aquatic mode of life, the body being 

 either long and cylindrical, or short and compressed, and frequently 

 there is a long, flat tail and a back crest of skin. Sometimes there 

 are no limbs, or only short fore-limbs, or the rudiments of fore 

 and hind limbs furnished with weak digits; 

 Q 241 



