OF NATURAL HISTORY. "St 



OF THE STRUCTURE AND ORGANS OF FISHES. 



It is one great and benevolent intention of Nature, that 

 no part of the univerfe ihould be deprived of inhabitants. 

 The earth, the air, the waters, are full of living beings, 

 who are not only confcious of their exiftence, but enjoy de-r 

 grees of happinefs proportioned to their natures, and the 

 purpofes they are deftined to anfwer in the general fcale of 

 animation. The different elements in which they live necef- 

 farily required a variety in their form, their food, and their 

 manners. The inhabitants of the earth and air have alrea- 

 dy been partially defcribed : Thofe of the waters are next 

 to be confidered. 



The bodies of moft fi.{hes are covered with a ftrong, 

 thick, flvin, in which numberlefs fcales are inferted in an 

 imbricated form, or like tiles on the roofs of houfes. Many 

 of them, and particularly thofe which are fhaped like the cod, 

 the trout, and the haddock, have a longitudinal line on each 

 fide. In thefe lines there are a number of fmall duch or 

 apertures, which throw out a mucous fubftance that lubri- 

 cates their fkins, and feems to anfwer the fame purpofes as 

 the mucous glands or ducSts placed in moft of our internal 

 prgans. 



Fiflies are deftitute of hands and feet. Their progreflive 

 motion, therefore, is performed in a manner different from 

 that of quadrupeds and birds. Their inflruments of mo- 

 tion are fins, or machines coniifling of a number of eiaftic 

 beams, connected to one another by firm membranes. Their 

 tails are of the fame texture. Their fpine is remarkably 

 flexible toward the pofterior part of the body, and here the 

 ftrongeft mufcies are likewife inferted. They have a power 

 of contra£ling and dilating their tails at pleafure •, by which 

 means, and by the afliilance of the fins, they move forward 

 in the fame manner as a boat with oars on its fides and a 

 rudder at its ftern. Fifhes have no neck : As they feciv 



