4 14 DESCRIPTION OF THE MUSEUM. 



nished the most interesting experiments on the 

 phenomena of the animal economy. It was by 

 dissecting frogs that gaivanism was discovered. 

 The Museum possesses more than twenty-five 

 species of frogs. The two most common in 

 France are the green and brown frogs : the 

 thighs of the first are esteemed good food. The 

 American species, called the bull-frog, is four 

 times larger than the green, and feeds on water- 

 fowl ; which it seizes by the feet, and drags 

 under water. A specimen of this voracious frog 

 is here seen, preserved in spirits of wine, into 

 which it was thrown when taken, at the time 

 it was endeavouring to swallow a duck, one 

 half of which had not yet been gorged. The 

 Cayenne frog, which is called Jackie , presents 

 the singularity of being smaller when at the 

 complete state of frog, than when at that of tad- 

 pole, owing to the transformation ; for when it 

 takes place, the branchiae y skin and tail, fall off 

 at once, and consequently the animal is reduced 

 to a smaller volume. To this difference of size, 

 existing between the perfect animal and its tad- 

 pole, may be attributed the errors some people 

 have fallen into, in taking the tadpole for the 

 full grown frog, and believing this last was 

 changed into a fish. The tree frogs (hylae), which 

 come next, differ from the rana ; they have the 



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