342 LABRADOR 
century, 1550-1590, 1660-1680, 1747-1808, 1857-1878, 
and also of recent years. Such large quantities have been 
~ taken in the North Sea these past two years that all previous 
records have been eclipsed. They disappeared from the 
Norwegian coast from 1655-1699, and again from 1784- 
1808. In 1871 they almost entirely disappeared again. 
The old theory that all the herring lived in one vast race 
in the polar seas and made a circular tour of the waters they 
are found in, was eloquently described by Buffon, but is 
now abandoned. There is little doubt that many separate 
shoals exist, and that they do not retire into ocean abysses, 
or mid-ocean, where they cannot be taken. When they 
leave the shore, they probably feed on the slopesin moderate 
depths near the coast they frequent. They have been 
captured in one hundred fathoms of water off the New- 
foundland coast. They are easily affected by temperature, 
preferring a temperature of 55° F. But they are caught in 
water as cold as 37° F., and the Scottish fishery is mostly in 
water at 41-42° F. 
The eggs (thirty-one thousand, on the average, to each 
fish) which sink and stick to the bottom are eaten in vast 
quantities by many species of animals in the waters. It 
is, obviously, of great importance that the egg stage should 
be as brief as possible. Nature seems to furnish the in- 
stinct, therefore, to seek water at 55° F., the optimum 
temperature for rapid hatching. In any case it is probable 
that in the Labrador polar current which carries the tem- 
perature of 30° F. in subsurface layers, the herring is not 
likely to breed at all. This view coincides with the actual 
observations that herring do not spawn north of the Mag- 
dalene Islands and the west coast of Newfoundland. 
