CHAPTER YII. 



INTELLIGENCE AND SPECIAL SENSES. 



Sense op Smell. 



The olfactory organ of fishes, "while being -well developed, 

 has no relation whatever Avith the function of respiration, 

 as in air-breathing animals. Dr. Giinther says : " It is 

 certain that fishes possess the faculty of perceiving odors, 

 and that various scents attract or repel them." This fact 

 is patent to all observant anglers, and has been since long 

 before the time of honest Izaak Walton. 



Sense of Sight. 



As the optic nerves of fishes show an extraordinary de- 

 velopment, we must naturally conclude that they are as 

 sharp-sighted in their element as Ave in ours. This, I think, 

 no experienced fly-fisher will deny ; yet it is the fashion 

 for biologists to accord to fishes only a moderate visual ca- 

 pacity, as compared with land animals. But good, simple 

 old Izaak Walton Avas much nearer the truth Avhen he said : 

 "A trout that is more sharp-sighted than any hawk you 

 have named, and more Avatchful and timorous than your 

 high-mettled merlin is bold." 



" In the range of their vision and acuteness of sight," 

 says Dr. Giinther, " fishes are very inferior to the higher 

 classes of vertebrates; yet, at the same time, it is evident 

 that they perceive their prey or approaching danger from a 



considerable distance." 

 (56) 



