GEM US PERCA. THE PERCH. 125 



Gen. I. Perca. — Sp. 1. P.fluviatilis. The Perch. 

 — As to the general appearance, the specific cha- 

 racters, and the varied garb in which this beautiful 

 fish appears, we, in this case, as in others, refer, as 

 previously stated, to our Appendix and Plate, under 

 the conviction that this will afford the most ample 

 satisfaction at once to the general reader and the 

 student of natural history. Varieties, however, 

 have been recorded, which it will here be proper to 

 notice. Mr. Pennant informs us, that in a lake 

 called Llyn Rathlyn, in Merionethshire, there is a 

 variety whose back is quite hunched, and the lower 

 part, near the tail, strangely distorted, the colour, 

 and other characters, remaining the same ; and the 

 normal variety occurring in the lake as abundantly 

 as the other. Linneeus had previously observed this 

 variety at Fahlun, in Sweden, and in other lakes 

 in the north of Europe ; and Pennant was informed 

 it occurred near Marlow, on the Thames. One of 

 this distorted race is figured by Mr. Daniel in his 

 Rural Sports. As to colour, again, specimens almost 

 entirely white have been noticed in particular soils, 

 as mentioned by Mr. Jesse in his Gleanings. Another 

 variety would appear to be of a uniform slate-grey 

 colour, with a silvery tint, as stated by Mr. Yarrell ; 

 these exist in the ponds of Ravenfield Park, near 

 Rotherham, Yorkshire, and the peculiarity is re- 

 tained when the living fish are transferred to other 

 waters. Once more ; Mr. Hartley makes the follow- 

 ing striking statement : — " There is certainly a very 

 extraordinary phenomenon attending the Perch of 



