224 SALMONIA. [XINTH 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 



