272 How to obtain it. 



close their eyes, but that they rest their bodies is very certain. 

 We know that they feel fatigue, and that they spend part of their 

 time in holes or under shady banks. They love shade, in fact, 

 and cannot do well without it. At night, when viewed by the 

 light of a lantern, a whole pond full may be watched at times 

 without their seeming to be in any way inconvenienced by the light. 

 They are at such a time often found to be in a perfectly quiescent 

 state, and also in the day-time I have seen a pond-full apparently 

 sleeping. The great difference between their sleep and that of 

 birds or animals is that they are apparently able to see at the same 

 time. We know well enough that all parts of the body do not 

 necessarily rest at once, and we also know that the sleep of a city 

 merchant and of a savage are two very different things. The 

 latter will almost sleep with his eyes open, and we can well under- 

 stand a fish being on the alert, even though asleep in the sense of 

 the body resting. 



The sense of taste and smell are to an extent existent in 

 trout. The nostrils are well developed, but have no communica- 

 tion with the mouth, nor are they used in any way for purposes 

 of breathing. Probably under some circumstances the power of 

 smell is useful to the fish in obtaining food, as for instance, in 

 blind examples which I have met with that have otherwise been 

 in excellent condition. The odour of water is naturally extremely 

 varied, according to the different ingredients or pollutions which 

 may exist in it. That trout are sensible of these variations there 

 is no room for doubt. They themselves give off odours and so do 

 other fishes, and I have long had reason for supposing that eels 

 can smell trout and follow them by scent. An otter can certainly 

 do so as I have found to my cost, and these animals on a stream 

 must become sensible of the presence of an unusual number of 

 fine trout kept in ponds near, the water from which is discharged 

 into the stream. 



Trout possess in a degree the sense of taste, but it cannot be 

 said to be at all well developed. They will accept some foods 

 while they reject others equally good or even better. This shows 

 that there must be a distinguishing power between one article of 

 food and another. Fish culturists know that when accustomed to 

 certain kinds of food they often refuse an article with which they 



