102 CLASS-BOOK OF ZOOLOGY. 



and has hind legs one foot and a half long. Its color is 

 brown, mixed with green ; yellowish-white beneath. It is 

 an inhabitant of the United States. Its flesh is very 



429. The Bullfrog, as well as all the other species 

 of frogs, deposit their spawn, which consists of a clus- 

 tered mass of gelatinous, transparent eggs, in num- 

 ber from 600 to 1,200, in the water, in the month of 

 March or April, according to the temperature of the at- 

 mosphere. 



§ 430. The spawn of the frog lies a month or longer, 

 according to the temperature of the water, before the 

 embryo is developed ; during which period each egg 

 gradually enlarges, and a few days before the time of 

 exclusion, the young animal may be perceived moving 

 about in the surrounding gluten. 



§ 431. When first hatched, they feed on the remains 

 of the gluten in which they were imbedded, and in the 

 space of a few days they will be found to be furnished 

 on each side of the head with a pair of ramified gills ; 

 in this state they are called Tadpoles. 



§ 432. The Tadpole, perfectly unlike the animal in a 

 complete state, consists merely of a large, roundish, black 

 head, and a slender tail. 



§ 433. Tadpoles are extremely lively in their motions, 

 and are often seen in such numbers, as to blacken the 

 water with their legions. They live on the leaves of 

 small water-plants. 



§ 434. When the Tadpole has arrived at the age of about 

 five or six weeks, the hind legs make their appearance, 

 gradually increasing in length and size. These, in about 

 a fortnight afterwards, are succeeded by the fore-legs : 

 the tail begins then to decrease, and altogether disappears 

 in the space of two days. 



§ 435. As soon as Tadpoles have lost their gills and 

 tail, and are provided with legs, they venture upon land ; 

 sometimes in such multitudes as to cover a space of many 

 yards in extent ; which phenomenon occasioned the popu- 

 lar belief, that frogs or toads descend from the clouds, 

 during showers. 



