152 COURAGE OF FISHES. 



their visual observatioiij let all the motions of 

 your body, as much as possible be of the same 

 "ghostly" order.* 



Herb. — Your own experiment, backed as it is 

 by the authorities you mention, convinces me 

 upon this subject. Henceforth, depend on it, I will 

 be quiet as a cat watching a mouse. But tell 

 me : I suppose you esteem the salmon a shy fish. 

 Is it more so than the trout ? 



Theoph. — Why, really, I cannot say ; there is 

 no great difference between them and other large 

 fish, in that particular. A pike is a bold fish if 

 he happen not to see you ; but let the shadow of 

 your little finger fail within his angle of vision, 

 which is much more extensive than ours, and 

 he's off like a shot. So, if a salmon happens to 

 catch a glimpse of you, he lies like a stone in the 

 deepest hole. If, therefore, any one be with you 

 as companion, or assistant, while fly-fishing, bid 

 him take it as no offence, if you desire him to 

 keep out of sight: for unthinking persons are too 

 apt to conclude that because they cannot see the 

 fish, there is no danger of the fish seeing them. 

 But it is a truism in optics, long since well-known 

 and very prettily exemplified by Mr. Ronalds, in 



* See further on tbe hearing of fishes, " Nollet on the Hearing of 

 Fishes." Mem. Fr. Acad. vol. 1 (1743), p. 199. " Anderson on the 

 same subject," ib. (1748) p. 149. "Hunter on the same," Phil. Tran, 

 (1782) p. 39. 



