224 SALMONIA. [NINTH DAY. 



and, as usually happens when small flies are used, 

 more fish escaped after being hooked than were taken 

 and these I found, the next day, were become as 

 sagacious as our Dove or Test fish, and refused the 

 artificial fly, though they greedily took the natural 



fly. 



PHYS. These fish, then, have the same habits 

 as our English salmons and trouts ? 



HAL. The principle to which I have referred in 

 two former conversations must be general, though it 

 has seemed to me, that they lost this memory sooner 

 than the fish of our English rivers, where fly-fishing 

 is common. This, however, may be fancy, yet I have 

 referred it to a kind of hereditary disposition, 

 which has been formed and transmitted from their 

 progenitors. 



PHYS. However strange it may appear, I can 

 believe this. 'When the early voyagers discovered 

 new islands, the birds upon them were quite tame, 

 and easily killed by sticks and stones, being fearless 

 of man ; but they soon learned to know their enemy, 

 and this newly acquired sagacity was possessed by 

 their offspring, who had never seen a man. "Wild 

 and domesticated ducks are, in fact, from the same 

 original type : it is only necessary to compare them, 

 when hatched together under a hen, to be convinced 

 of the principle of the hereditary transmission of 



