AMPHIBIA. 



HE title Amphibia applied to this class of ani- 

 mals by Linnaeus, may perhaps be considered as 

 not absolutely unexceptionable ; the power of liv- 

 ing with equal facility both in land and water 

 being not granted to all the animals which com- 

 pose it. Yet, since it is certain that the major 

 part are found to possess that faculty in a consider- 

 able degree, the title may be allowed to continue. 



The Amphibia, from the peculiar structure of 

 their organs, and the power which they possess of 

 suspending respiration at pleasure, .can not only 

 support a change of element uninjured, but can 

 also occasionally endure an abstinence which 

 would infallibly prove fatal to the higher order of 

 animals. 



It has been a general doctrine among anato- 

 mists, that the hearts of the Amphibia were, in 

 the technical phrase, unilocular, or furnished with 

 only one ventricle or cavity : a doctrine main- 

 tained by many eminent anatomists, and, in ge- 

 neral, assented to by the greatest physiologists, as 



v. in. P. i. 1 



