58 The British Naturalist, 



range of its beak. Instantaneously it darts, and the prey is secured. 

 That it should fish only in the absence of the sun, is also a wonderful 

 instinct. Every one who is an angler, or is otherwise acquainted with the 

 habits of fish in their native element, knows how acute their vision is, and 

 how much they dislike shadows in motion, or even at rest, projected from 

 the bank. It is not necessary that the shadow should be produced by the 

 bright sun ; full daylight will do it ; and we have seen a successful fly- 

 fishing instantly suspended, and kept so for a considerable time, by the 

 accidental passage of a person along the opposite bank of the stream ; nay, 

 we once had our sport interrupted by a cow coming to drink ; so alarmed 

 are fish, especially the trout and salmon tribe, at the motion of small 

 shadows upon the water, though shadow, generally speaking, be essential 

 to their surface-operations. They do not feed, and therefore we may con- 

 clude that they do not so well discern [?] small bodies upon the surface, 

 when the sun is bright. Fishes are, in fact, in part, nocturnal animals ; 

 and the heron, that lives upon them, and catches them only in their feeding- 

 places, is partially, also, a nocturnal animal. There is one case in which 

 we have observed herons feeding indiscriminately in sun and shade ; and 

 that is, when a river has been flooded to a great extent, and the flood has 

 passed off, leaving the fish in small pools over the meadows. How the 

 herons find out these occasions it is difficult to say; but we have seen 

 several pairs come after a flood to a river which they never visited upon 

 any other occasion, and within many miles of which a heronry, or even the 

 nest of a single pair, was never observed." (p. 106 — 108.) 



" The case char (Sahno alpinus)," we are informed, '* is 

 found chiefly, if not exclusively, in Winander-mere." If by 

 this be meant the fish usually known by the name of char in 

 the north of England (of which, however, from the account 

 here given, we entertain some doubt), it occurs more particu- 

 larly in Coniston and Buttermere lakes. The char which 

 we have there seen has the eyes remarkably prominent ; the 

 back rises more into an arched form than that of the trout, 

 and the belly is rather concave to correspond ; so that the 

 whole fish is in the form of a gentle curve, or a bow slightly 

 bent. We did not know that our char ever entered the salt 

 water. It certainly is a most excellent fish; superior, we 

 think, to the trout, and deservedly esteemed, independently 

 of its rarity. We apprehend our author must be speaking 

 of a different species. The genus ^Salmo still requires much 

 investigation ; the true diagnosis of the species being a per- 

 plexing knot in natural history, which has not yet been 

 unravelled. 



Variety, and species, and even genus, are terms continually 

 used synonymously in ordinary conversation ; and it is quite 

 surprising to see how little their true meaning, as employed 

 in natural history, is generally understood, even by people of 

 education. But we should not have expected that an accom- 

 plished naturalist would have committed the vulgar blunder 

 of confounding these terms ; yet so it is. '' Of the dragon 

 fly (Libellula)," we are told, «« there are several varieties," 



