368 NATURAL HISTORY. 



twenty inches. These large specimens are not common, and usually but 

 one or two will be found in possession of a pond. Their note is very aptly 

 compared to the bellowing of a bull ; for, with the exception of the spade- 

 foot toad, the bull-frog is the loudest voiced of any of our amphibians. 

 During the day he keeps quiet or utters only an occasional croak, but at 

 dusk, especially in early summer, his loud metallic voice drowns all the 

 other choristers of the pond. 



The bull-frog lays its large masses of eggs, enveloped in a gelatinous 

 matrix, in the spring ; the tadpoles soon hatch out and eat everything 

 which comes in their way. With their horny jaws they attack decaying 

 animals and plants, scraping away the soft parts little by little, until at 

 last but the hard, indigestible portions remain. The anatomist frequently 

 takes advantage of this and sinks the animal of which he desires the 

 skeleton in a pond filled with tadpoles of various sorts. In a short time 

 every particle of flesh has been torn and gnawed away, leaving naught but 

 the bones and ligaments behind, but these in perfect condition. While the 

 tadpoles of most frogs go through then changes in a single season, those 

 of the bull-frog last through the winter, and through the ice one can see 

 them wriggling about and following the same life as in the warm days of 

 summer. 



It is beyond our province to describe the various species of our common 

 frogs, — the green frog, marsh-frog, leopard-frog, and the like. Each has 

 its favorite habitat, and each utters its own peculiar note. All are carniv- 

 orous, and anything — insects, fishes, tadpoles, or worms — that comes in 

 their way is eagerly devoured. All are edible, and nothing is more pala- 

 table than a mess of frogs' legs, properly cooked. 



C^ECILIANS. 



Strangest of all the amphibians are the worm-like Caecilians of tropical 

 countries. The casual observer would not in the least suspect that they 

 have the slightest relationship to the frogs and salamanders, but would 

 rather regard them either as worms or as snakes. They have long and 

 worm-like bodies, and are without any traces of limbs. Their eyes are 

 rudimentary, or these animals may be entirely blind, a fact alluded to in 

 the name given them, which is derived from the Latin ccecum, blind 

 And yet in all their anatomy they show resemblances to the salamanders. 

 Even in their growth they pass through similar stages, having at one time 

 gills ; these organs being like the fringes of the Necturus, or the mud-eel, 

 or axolotl, in the walls of which the blood-vessels ramify. In the adult 

 condition they breathe by lungs, like any frog or salamander. The species 



