126 ACANTHOPTERYGII. PERCH FAMILY. 



Malham Water, Yorkshire, the cause of which I 

 leave to Naturalists to ascertain. After a certain 

 age they become blind ; a hard, thick, yellow fibre 

 covers the whole surface of the eye, and renders the 

 light totally obscure. "When this is the case, the 

 fish generally are exceedingly black ; and although, 

 from the extreme toughness and consistency of the 

 membrane, it is evident that some have been much 

 longer in this state than others ; yet there appears 

 to be no difference either in their flavour or con- 

 dition." 



The Perch, under favourable circumstances, attains, 

 with years, to a very considerable size. When three 

 pounds weight it is considered of a large size ; but 

 those of five pounds are by no means uncommon, 

 having been found in Ulls water, as mentioned by 

 Mr. Hutchinson in his History of Cumberland, and 

 by Dr. Parnell in Loch Lomond, and by numerous 

 other observers. They have been frequently seen 

 of the size of six and eight pounds ; and Mr. Pen- 

 nant mentions his having heard of one taken in the 

 Serpentine, Hyde Park, which weighed nine pounds. 

 As it respects their spawning, they are both pro- 

 lific and precocious. Mr Jesse states that he has 

 known them full of spawn when they were not more 

 than three inches long ; a Perch of half a pound 

 weight has been found to contain 280,000 ova, and 

 the number has been estimated in larger ones at 

 nearly a million. Aristotle noticed, that the female 

 deposits her ova united together by a viscid matter 

 in lengthened strings ; and Bloch remarked the same 



