348 GENERAL ZOOLOGY 



South American species, the famous Surinam toad (Pi'pa 

 pipa), the eggs are spread by the male over the back of the 

 female, where each egg becomes covered with a growth of 

 skin, forming a pouch with a lid. Here development goes 

 on, and the entire metamorphosis takes place within the 

 egg. In a Chilean species (Rhinoder 1 'ma dar'wini) the eggs 

 are transferred by the male to vocal sacs at the side of the 

 mouth, which become greatly developed at the breeding 

 season. Metamorphosis takes place within these sacs, and 

 the young escape in the adult condition. In half a dozen 

 species of tree frogs from South America (Nototre'ma) the 

 females possess dorsal pouches in which the eggs are placed. 

 The young appear either as tadpoles or as perfect frogs. 



The tree frogs, or tree toads, are forms adapted to life in 

 trees. They possess soft pads on the ends of the fingers and 

 toes. Many of them, like our common tree toad (Hyla 

 ver'sicolor, Fig. 178), are protectively colored, and have the 

 power of changing their color through various shades of gray 

 and green. Several of our smaller species of tree toads, 

 called "peepers" in the country, give utterance to shrill 

 notes, which are among the first sounds of spring. In that 

 season they seek the ponds to mate and lay their eggs. 



The common toad (Bu'fo americanus) is one of the 

 farmers' most valuable allies in the destruction of injurious 

 insects. Usually the toads feed continuously throughout 

 the night. It has been estimated that in a single night a 

 toad consumes insects enough to equal four times the ca- 

 pacity of its stomach. Despite the prejudice which its 

 appearance still excites among those who do not understand 

 it, the animal is a most interesting object for study. There 

 is no truth in the oft-repeated statements of its poisonous 

 qualities, except in so far as the acrid secretion of the skin, 

 which is a protection to many amphibians, might be in- 

 jurious if it got on sensitive surfaces, such as the lining of 



