HEREDITARY INSTINCT. 221 



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 



Phys. — These fish, then, have the same 

 habits as our English salmons and trouts ? 



Hal. — The principle to which I have re- 

 ferred in two former conversations must be 

 general, yet 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 disposi- 

 tion, which has been formed and transmit- 

 ted 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, 



