156 TRANSFORMATION OF ANIMALS. 



off and renewed. Similar changes take place in quadrupeds 

 of every denomination ; with examples of which every man's 

 experience and recollection will readily supply him; and 

 therefore, it is unnecessary to be more particular. 



Neither are birds, in their progress from birth to maturity, 

 exempted from changes. Like quadrupeds, many birds are 

 blind for some time after they are hatched. In this condition, 

 how different are their form and appearances from those of 

 the perfect animals ! At first they are covered with a kind 

 of down instead of feathers. Even after the feathers shoot, 

 they are often of a color different from that which they ac- 

 quire when full grown. The beautifully variegated colors of 

 the peacock's tail appear not till he arrives at his third year. 

 Birds that have crests, or wattles, live a considerable time 

 before they acquire these ornaments or marks of distinction. 

 All birds annually moult, or cast their feathers, in the same 

 manner as quadrupeds shed their hair ; the new pushing out 

 the old. 



Frogs, toads, and some other reptiles, undergo great changes 

 in their form and structure. When it first escapes from the 

 egg, a frog appears in the form of a tadpole, an animal with 

 a large, roundish head, and a compressed or flat tail, but 

 totally destitute of feet and legs. In this state it remains a 

 considerable time, when the two fore feet begin to shoot, and 

 have an exact resemblance to the buds of trees. As their 

 growth advances, the toes and legs are distinguishable. The 

 same process goes on with the hind legs, only they are some- 

 what later in making their appearance. During the growth 

 of the legs, the blood being drawn into different channels, 

 the tail suffers a gradual mortification, till at last it totally 

 vanishes, and the tadpole is metamorphosed into a quadruped. 

 Tadpoles never come out of the water ; but after their trans- 

 formation into frogs, they become amphibious, and occasion- 

 ally frequent both land and water. 



' In the species of frog called Ran a paradoxa, or the para- 

 doxical frog, the animal in its tadpole state grows to its full 

 size, before the change takes place. Having in almost all 

 respects the appearance of a fish, it has been supposed by the 

 vulgar to be a frog turned into a fish, and hence has been 

 called the frog-fish. In time, however, it undergoes the 

 usual changes, and becomes a true frog. It inhabits Surinam. 

 tn a species of toad, also found in Surinam, the whole process 

 of metamorphosis, from the egg to the perfect state, is carried 

 on upon the back of the parent animal. The egg is depos- 



