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 on 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 capture individuals. 
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 Salmonide 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, guinnat, 
