Sight of Fishes. 39 



the habits of the animals, we have the clearest 

 evidence before us that the faculty of sight in fishes 

 is one of their highest sentient endowments." x 



Dr Giinther, in his ' Study of Fishes,' while ad- 

 mitting that in the range of their vision and acute- 

 ness of sight fishes are very inferior to the higher 

 classes of vertebrates, says : " At the same time it 

 is evident that they perceive their prey or approach- 

 ing danger from a considerable distance ; and the 

 discrimination with which they sometimes prefer 

 one colour or kind of artificial fly to another, affords 

 sufficient evidence that the vision, at least of cer- 

 tain species, is by no means devoid of clearness 

 and precision." 2 The recent researches of Mr Dal- 

 rymple reveal the existence of particular muscles 

 controlling the position of the lens of the eye of 

 many fishes, and thus modifying the angle of vision 

 for varying distances, precisely as the ciliary muscle 

 of the human eye regulates the form of the lens, 

 and adapts it to the required focus. 



Much easy satire and some cheap raillery have 

 been expended on the angler who, in insisting on an 

 exact imitation of a fly, would seem to credit trout 

 with an extensive practical entomological know- 

 ledge of its natural prey. But mere theorists are not 

 very likely to discover what amount of entomological 



1 Handbook of Angling, p. 292. 

 Ill, 112. 



