14 OBSERVATIONS 



strict inspection of almost every little object 

 which floated down the stream, taking it into 

 the mouth, sometimes with avidity, sometimes 

 more slowly, or cautiously, as if to ascertain its 

 fitness, or unfitness, for food, and frequently to 

 eject it instantly. 1 This seems to favour the 

 notion, that if the Trout has not a taste similar 

 to our own, he may be endowed with some equi- 

 valent species of sensation. It may also account 

 for his taking a nondescript artificial fly ; but it 

 furnishes no plea to quacks and bunglers, who, 

 inventing or espousing a new theory, whereby 

 to hide their want of skill or spare their pains, 

 would kill all fish with one fly, as some doctors 

 would cure all diseases by one pill. If a Trout 

 rejects the brown hive bee at the time that he 

 greedily swallows the M.&rch-brown fly, it is 

 clear that the imitation should be as exact as 

 possible of the last, and as dissimilar as possible 

 to the first. 



I have very frequently watched fish in an 

 apparently hesitating attitude when Bees and 

 Wasps were within their ken. How far either 

 smell or taste may be concerned in this seeming 

 indecision I cannot determine. 



On one occasion I observed a Humble Bee 

 which floated down the stream visited by Trout, 



1 After having, perhaps, appropriated some little insect em- 

 barked upon it. 



