AMERICAN INSTITUTE. 477 



lation and a sucker. Thus God limits the inroads of voracious 

 fish, and gives each individual species an opportunity of escape. 



The teeth of fish, like those of terrestrial animals, may be 

 divided into molary, incisive, and laniary, distributed according 

 to mode of life and species : the palate, tongue and throat are 

 often armed with them; some are immovable in their sockets, 

 and others may be depressed and elevated at the will of the 

 owner. There are herbivorous fish that have three rows of molar 

 teeth. The jaw of some such fish was found in British North 

 America with six rows of molar teeth. 



There are other fish that migrate when the waters of their 

 native ponds dry up, and march by land in search of others. 

 They travel in large droves, generally at night, with a motion like 

 a two-footed lizard. A strong arm constitutes the first ray of the 

 pectoral fin; using this as a foot, they thrust themselves forward 

 with their tail, which is elastic, almost as fast as a man can walk. 

 It is supposed that they are furnished with a supply of water, 

 retained by some internal arrangement, from the fact that when 

 taken up and rubbed perfectly dry, they become moist imme- 

 diately after. 



Without the cooperation of a liquid, fish cannot expand the 

 apparatus on which the blood vessels depend for distribution. 

 When taken from the water, this effect cannot be produced, and 

 the fish fails, after reiterated exertion, to raise the bronchise, and 

 dies from suffocation. I have killed a fish almost instantaneously 

 by preventing the expansion of the bronchi8e,by passing a ligature 

 around the opercula. The surface of the gills in the skate is fully 

 equal to the entire surface of the human body, and it has been 

 supposed that they, as well as nearly all other fish, ejected the 

 respired water through the nostrils; but this cannot possibly be 

 the case, as I have never been able to discover any communica- 

 tion between the nostril and the mouth of any fish. 



The electric fish are emulated by a small one of a different 

 tribe, that catches its prey, chiefly flies, by throwing upon them 

 a gross substance that causes their wings to adhere together. 

 They are called fly-shooters, and are remarkable for their very 

 singular form, brilliant colors, and the quickness of their graceful 

 movements. 



