530 Fishes. 



I could only guess. But one day while watching an eel thus employ- 

 ed, I saw a loach make its appearance from the stone under which the 

 eel had thrust its head, and hastily seek refuge under another stone at 

 no great distance. The eel instantly followed it ; dislodged it again, 

 and pursued it to its next hiding-place; moving at the same time much 

 more quickly than it had been doing before it started its game. It 

 was in short a regular hunt, and perseveringly prosecuted withal. 



I also very frequently noticed another of the evolutions of this fish, 

 performed when it was moving about in the manner above noticed. 

 It might be seen suddenly to raise its head and neck, and dig, as it 

 were, into the gravel and sand of the river-bed ; at the same time 

 throwing itself on one side, so that the white of the belly was plainly 

 seen, while a waving motion, like that of a streamer moved by a gen- 

 tle wind, went through the length of the body. The head was thrust 

 downwards with energy ; and much the same kind of effort seemed to 

 be made as that a dog employs when catching a mouse in straw or 

 long grass. I took for granted the fish was engaged in taking prey of 

 some kind : I could not, of course, see what it was ; most probably 

 w r ater-insects or larvae w 7 hich shelter amongst the stones. 



Some naturalists I believe scout the idea that fish may be possessed 

 of olfactory organs of strong power ; and others maintain it. Among 

 anglers the notion seems to be losing ground ; for whereas in old fish- 

 ing-books one finds multitudes of recipes for rendering the bait more 

 attractive by imparting to it some powerful odour ; modern ones say 

 little or nothing on the subject. Mr. Ronald's experiments seem to 

 prove either that the trout has no power of smelling, or that he has no 

 dislike either to the scent or the taste of mustard and cayenne pepper. 

 But in the loach-hunt it certainly seemed that the eel had some other 

 guidance than that afforded by his sight ; for having dislodged a loach 

 which issued from one side of the stone, the eel being on the opposite 

 side; yet the latter almost always went (and with accelerated motion) 

 direct to the fresh hiding-place of the former. 



That the eel is justly charged with destroying great quantities of 

 the fry of other fish, cannot, I suppose, be doubted ; but at what pe- 

 riod in the life of the fry the destruction is committed, is not so easily 

 settled. I believe it to be at a very early period ;* and that later, when 

 the young fish have acquired sufficient strength and size to leave the 



* Thus Mr. Shaw says of the young of the salmon, that they take advantage of any 

 inequality in the bottom of the river, such as the print of a horse's hoof, to shelter 

 themselves in it : and other instances will strike every one accustomed to walk along 

 the shallow edges of streams or ponds. 



