258 PIKE AND OTHER COARSE FISH. 



appearance of glittering festoons of pearls. Perch spawn, at 

 any rate when deposited in confinement, vivifies in from seven 

 to seventeen days. This is the statement of James Tennant, 

 keeper at the Zoological Gardens aquarium. 



It was maintained by the ancients that the perch was self- 

 productive ; an opinion confirmed by Carolini and Valenciennes. 

 In recent times the point has, however, been satisfactorily set at 

 rest by the researches of M. Duffosse, extending over no less 

 than 368 specimens of Perridiz. He not only proved them to be 

 normally unisexual, but observed them depositing their ova, and 

 at the same time casting their milt. Notwithstanding, there- 

 fore, Mr. Darwin's dictum against the structure of any animal 

 being such as to insure self-fertilisation, it would seem that in this 

 case there is every reasonable ground for supposing it to be so. 



Though attaining their greatest perfection in clear, sharp 

 streams, perch thrive well on clayey or sandy bottoms, pre- 

 ferring generally a water of a moderate depth and current, and 

 frequenting holes, mill-dams, hollow banks, and in summer, the 

 undercurrents of weirs. In winter their favourite haunts are 

 backwaters and eddies ; and at this time of the year they feed 

 best about the middle of the day, more particularly if bright and 

 warm. They usually go in large shoals, and in Lough Corrib 

 and other places that I am acquainted with, it is customary to 

 try and discover the position of the .shoals in the lough before 

 attempting to begin fishing. When the perch cease biting it is 

 assumed that they have moved on to other grounds, and great 

 efforts are made to keep on their track. 



There is a small species of the perch family, and in ap- 

 pearance very much resembling it, called the ruffe or pope, 

 which is very apt to be taken occasionally by the angler when in 

 pursuit of other fish, and especially after raking fur gudgeon. 

 The distinctive mark between the perch and the ruffe consists 

 in the back fin, whit h in the perch is in two clearly separated 

 portions, and in the ruffe is joined into one. The ruffe also, 

 though resembling the perch in most of its characteristics diffeis 

 from it, in that it apparently thrives only in running wateis, 



