4IO THEPHILOSOPHY 



inftindb is affifted by the inftrudlion of the parents ; for the young 

 are no fooner able to fly, than the parents, by the force of example, 

 teach them to refort to trees, and to infert their tongues indifcrimi- 

 nately into every hole or fiflure. 



Of the oeconomy of Fijhes, as formerly remarked, our knowledge 

 is extremely limited. But, as the ocean exhibits a perpetual and a 

 o-eneral fcene of attack and defence, the arts of alTault and of eva- 

 fion muft, of courfe, be exceedingly various. For the prefervation 

 of fome fpecies of fillies, Nature has armed them with ftrong and 

 fharp pikes. Others, as the perch-kind, are defended with fl:rong 

 bony rays in their fins. Others, as the univalve fhell-filh, retire in- 

 to their fhells upon the approach of danger. The bivalves and mul- 

 tivalves, when attacked, inftantly fhut their fhells, which, in general, 

 Is a fufficient protection to them. Some univalves, as the limpet- 

 kind, attach themfelves fo firmly, by excluding the air, to rocks and 

 ftones, that, unlefs quickly furprifed, no force inferior to that of 

 breaking the fhell can remove tliem. The fiying-fifh, when purfued, 

 darts out of the water, and takes refuge in the air, in which it is for 

 fome time fupported by the operation of its large and pliable fins. 

 The torpedo is furnifhed with a remarkable apparatus for felf-prefer- 

 vation : It repels every hoftile attempt by an eledtrical ftroke, which 

 confounds and intimidates its enemies. Several fifhes, and particu- 

 larly the falmon kind, when about to generate, leave the ocean, 

 afcend the rivers, depofit their eggs in the fand, and, after making 

 a proper nidus for their future progeny, return to the ocean from 

 whence they came. Others, as the herring-kind, though they fel- 

 dom go up rivers, afl"emble in myriads from all quarters, and ap- 

 proach the {hores, or afcend arms of the fea, for the purpofe of pro- 

 pagating the fpecies, and cherifhing their offspring. When that 

 operation is performed, they leave the coafts and difperfe in the 

 ocean, till the fame Inftindive impulfe forces them to oblerve a fimi- 



lar 



