448 ZOOLOGY. 



spring in immense schools, in which the females are three 

 times as numerous as the males, to spawn, selecting shoal 

 water from three to four fathoms deep in bays, where the 

 eggs hatch. At this season, and early in the summer, hun- 

 dreds of millions are caught, especially 011 the Canadian,. 

 Newfoundland, and Labrador coasts. The English white- 

 bait is the young of the herring. The herring is caught in 

 deep nets with meshes large enough to capturenndividuals 

 ,of ordinary size, the nets having a finer mesh than those 

 used for the mackerel fishery. 



The alewife and shad are said to be anadromous, from 

 their habit early in spring of visiting the coast and ascend- 

 ing rivers in vast numbers to spawn. The eggs are of mod- 

 erate size ; the ovaries are said to contain about 25,000, and 



Fig. 403. The Herring, Clupea harengus, one third natural size. From the Ameri- 

 can Naturalist. 



at times as many as 100,000 or 150,000 eggs. They are dis- 

 charged near the surface, sinking slowly to the bottom. 

 The time between impregnation and hatching varies from 

 about three to six days, according to the temperature. The 

 shad eats little or nothing in fresh water, being then engaged 

 in the act of reproduction. In the sea they live on small 

 Crustaceans, such as Mysis, etc. The menhaden is now put 

 up as a substitute for sardines, and is of great value as fish- 

 bait, especially in the mackerel fishery, and for its oil. 



The family Salmonidce comprises the salmon, trout, and 

 whitefish. with a number of species and varieties. The 

 species of the genus Salmo have not more than eleven rays 

 to the anal fin, while the salmon of the west coast, quinnat., 



