CLASS AMPHIBIA 



367 



secretions. Examples of such are the thyroid glands, one of which is 

 situated ventrally on each side of the body in the region of the throat. 

 Others are the thymus glands, which he below and behind each tympanum, 

 and adrenal bodies, one on the ventral side of each kidney. 



The tree frogs, or tree toads (Fig. 248), possess dilated adhesive 

 discs upon the toes. Among these types is an interesting tree frog 

 found in Brazil which makes a nest for its eggs and young at the bottom 

 of a pond, building a mud wall about it; another frog found in Venezuela 

 carries its eggs and young in a shallow pouch on its back until the latter 

 are almost ready for metamorphosis; and still another found in Java has 

 greatly enlarged feet, the toes being connected by webs, making it pos- 

 sible for the animal to glide or sail through the air for a considerable 

 distance. A curious little tree frog found on the island of Martinique 



Fig. 248. — Common eastern tree 

 toad, Hyla versicolor lueConto. Male, 

 from Staten Island, New York. 

 X /3. {Redrawn from Dickerson, 

 "Frog Book.") 



Fig. 249. — Asiatic cecilian, Ich- 

 thyophis sp., with eggs. {Modified 

 from Thompson, " Outlines of Zoology," 

 after P. and F. Sarasin.) 



glues its eggs to a leaf, where they form a foamy mass. In this case 

 development is practically completed in the egg and there is no aquatic 

 larval period. Thus some of these forms have practically emancipated 

 themselves from any need of an aquatic environment, though they must 

 still live in a moist locality. 



395. Apoda. — The Apoda, or cecilians, sometimes called blindworms, 

 are generally distributed in tropical and subtropical countries. They 

 possess neither girdles nor limbs but have concealed dermal scales. 

 They burrow in the earth somewhat as does an earthworm and are not 

 unlike an earthworm in general appearance. The mouth is at one end 

 of the body and the anal opening almost at the other, there being merely 

 a rudiment of a tail. The eyes are also rudimentary and practically 

 functionless, but the animal possesses a protrusible tentacle-like organ 

 lying in a groove between the eyes and nose by means of which it feels 

 its way about. In one type found in southern and southeastern Asia 



