134 OF INSTINCT. SECT. XVI. 14. 3 . 



to prey upon the latter, and in fome years devour fuch immenfe 

 quantities as to render this fifhery more expenfive than profita- 

 ble. 



3. Theremora, when he wifhes to remove his fituation, as 

 he is a very flow fwimmer, is content to take an outfide place 

 on whatever conveyance is going his way ; nor can the cunning 

 animal be tempted to quit his hold of a fhip when (he is failing, 

 not even for the lucre of a piece of pork, left it fhould endan- 

 ger the lofs of his paflage : at other times he is eafily caught with 

 the hook. 



4. The crab-fifh, like many other teftaceous animals, annu- 

 ally changes its fhell ; it is then in a (oft flare, covered only 

 with a mucous membrane, and conceals itfelf in holes in the 

 fand or under weeds ; at this place a hard (helled crab always 

 ftands centinel, to prevent the fea infe&s from injuring the other 

 in its defencelefs ftate ; and the fifhermen from his appearance 

 know where to find the foft ones, which they ufe for baits in 

 catching other fifh. 



And though the hard flielled crab, when he is on this duty, 

 advances boldly to meet the foe, and will with difficulty quit 

 the field ; yet at other times he fliews great timidity, and has a 

 wonderful fpeed in attempting his efcape ; and, if often inter- 

 rupted, will pretend death like the fpider, and watch an oppor- 

 tunity to fink himfelf into the fand, keeping only his eyes above. 

 My ingenious friend Mr. Burdett, who favoured me with thefe 

 accounts at the time he was furveying the coafts, thinks the 

 commerce between the (exes takes place at this time, and in- 

 fpires the courage of the creature. 



5. The (hoals of herrings, cods, haddocks, and other fiili, 

 which approach our ihores at certain feafons, and quit them at 

 other feafons without leaving one behind ; and the falmon, that 

 periodically frequent our rivers, evince, that there are vagrant 

 tribes of fifh, that perform as regular migrations as the birds of 

 paflage already mentioned. 



6. There is a cataract on the river Liffey in Ireland about 

 nineteen feet high : here in the falmon feafon many of the inhab- 

 itants amufe themfelves in obferving thefe fifh leap up the tor- 

 rent. They dart themfelves quite out of the water as they af- 

 cend, and frequently fall back many times before they furmount 

 it, and balkets made of twigs are placed near the edge of the 

 ft ream to catch them in their fall. 



I have obferved, as I have fat by a fpout of water, which de- 

 fcends from a ftone trough about two feet into a ftream below, 

 at particular feafons of the year, a great number of little fifh 

 called minums, or pinks, throw themfelves about twenty times 



their 



