250 ANIMAL INTELLIGENCE. 



miles a day ; in a smooth stream or lake their progress would 

 increase in a fourfold ratio. Their tail is a very powerful organ, 

 and its muscles have wonderful energy ; by placiug it in their 

 mouths they make of it a very elastic spring, for letting it go 

 with violence they raise themselves in the air to the height of 

 from twelve to fifteen feet, and so clear the cataract that impedes 

 their course : if they fail in their first attempt, they continue 

 their efibrts till they have accomplished it.^ 



General Intelligence, 



With reference to the general intelligence of fish, 

 allusion may first be made to their marked increase of 

 wariness in waters which are much fished. This shows no 

 small degree of intelligence, for the caution is proved to 

 be the result of observation by the fact that young trout 

 under such circumstances are less wary than old ones. 

 Moreover, many fish will abandon old haunts when much 

 disturbed. Again, according to Kirby, the carp thrusts 

 itself into the mud in order that the net may pass over it, 

 or, if the bottom be stony, makes great leaps to clear it. 



At the Andaman Islands fish are captured by the convicts 

 by means of weirs fixed across the openings of creeks. After 

 existing a week or so, it is observed that captures invariably 

 cease; and it is believed that such is due to barnacles, &c., 

 clustering on to the wood of which they are composed. It does 

 not seem improbable that the fish have learned to avoid a loca- 

 lity out of terror at those which enter but do not again return.^ 



Lacepdde^ relates that some fish, which had been kept 

 for many years in a basin of the Tuileries, would come 

 when called by their names. Probably it was the sound 

 of the voice and not the articulate words to which they 

 responded ; for Lacepede also relates that in many parts 

 of Grermany trout, carp, and tench were summoned to 

 their food by the sound of a bell ; and the same thing has 

 been recorded of various fish in various localities, notably 

 by Sir Joseph Banks, who used to collect his fish by sound- 

 ing a beU.'* 



* Kirby, Hist. Hahits and Instincts of Animals, vol. i. p. 119. 



2 F. Day, loc. cit. * Hist, des Poiss., Introd., cxxx. 



* For sundry other similar cases see Mr. Day's excellent paper 

 already quoted. 



