THE YELLOW PERCH. 



You'll prosper, master of the camp with ease ; 

 For, like the wicked, unalarmecl they view 

 Their fellows perish, and their path pursue."* 



Day tells us that in the famous Norfolk Broads the fish assemble in shoals 

 according to their sizes, the smaller and larger individuals keeping to 

 themselves, and repelling the intrusion of those that materially differ from 

 themselves in this respect. The writer has observed a similar natural 

 .association in the lakes of the Hudson and Housatonic basins. In winter 

 they retreat to the deepest parts of their domain. Here they adapt 

 themselves to circumstances; if the temperature of the water approxi- 

 mates the freezing point, they become torpid ; if it remains above 38 or 

 40 F. , they do not suffer any inconvenience. Dr. Abbott found a large 

 number of them in December and January, in a deep hole in the bed 

 of a tide-water creek, about half an acre in extent and twenty feet deep ; 

 they were in moderately good condition, active and in high color, with 

 empty stomachs, and refusing to feed, a habit by no means invariable, 

 however, at this season. 



As spring advances they assume their ordinary mode of life. With the 

 warming of the waters the eggs begin to swell in the ovaries', the colors 

 brighten, particularly in the males, and the lower parts of the body in 

 both sexes assume a ruddy hue. Spawning time varies in different locali- 

 ties. It is of course largely dependent upon the temperature of the water, 

 though the requisite standard of heat most probably changes with latitude. 

 In New Jersey, according to Abbott, it comes in May, with the water at 

 55 F., and in Sweden, by Malm's observations, in May, also, at 50 F. In 

 Virginia and Maryland Perch spawn in March and April ; in France and 

 Austria, from March to May ; in England and Sweden, in April and May. 

 When the Marsh, Marigold, or " Cowslip," Caltha palustris, blooms in the 

 wet meadows, the spawning time of the Perch is near at hand. That 

 Perch spawn twice in the year, is a popular belief in Europe. This idea 

 must have originated in the fact, well known to students of fish, that many 

 individuals retain their eggs long after the end of the normal spawning time. 



Among some Perches, twenty millimeters long, taken late in September, 

 1866, in the Rhine, a French naturalist found three males prepared 

 for breeding as well as a female with ovaries hardly visible. 



The proportion of males to females varies curiously with locality. Out 

 of one hundred taken at Salzburg only ten were males, and Cuvier stated 



*Oppian's Halieutics. 



