272 SUPPLEMENT ON 



rubs herself against rushes and hard bodies, to facilitate 

 its exclusion. The eggs are linked together, forming a sort 

 of chaplet like that of the spawn of frogs and toads, four 

 or five being inclosed in one common membrane, giving 

 to the mass the appearance of hexagonal meshes ; each egg 

 is about the size of a poppy-seed, but they vary greatly in 

 number. Harmer, Bloch, and Gmelin state, that there are 

 about 300,000 in a perch of half a pound weight. Picot has 

 counted 992,000 in a fish weighing about a pound ; and 

 Rousseau the elder found only 69,21(5 in another of nearly 

 the like weight. 



The perch is eminently predatory, devouring with avidity 

 the young and the weak of most animals of its class, as well 

 as water-lizards, frogs, small snakes, aquatic insects, worms, 

 naked mollusca, &c. They may be seen in summer spring- 

 ing from the surface of the water, in pursuit of gnats and flies ; 

 indeed, so voracious are they at times, that they will preci- 

 pitate themselves on animals, whose means of defence are too 

 effectual for them ; and thus they have been found dead, ap- 

 parently of hunger, with a stickleback in the mouth, whose 

 dorsal spine was stuck through the palate of the perch. It is 

 not, however, in its turn, without powerful enemies, notwith- 

 standing the formidable character of its dorsal spines ; as it 

 frequently falls a prey to pike, large eels, and trout, as well as 

 to the web-footed and wading birds. A small crustaceous 

 animal also, cymothoe, insinuating itself into the delicate 

 tissue of the gills, destroys many of them. When the water, 

 moreover, is frozen for a time, they become swollen, and the 

 mucous membrane which covers the cavity of the mouth, and 

 another over the extremity of the rectum, enlarge and form 

 bags, and unless air be admitted, they soon perish. At this 

 time they may be taken even with the hand, if a hole be made 

 in the ice, to which they will repair with eagerness. Some 



