98 
HERRING. 
under different circumstances of spawning. We cannot venture 
to draw any conclusion from such variations with regard to 
the extent of their wanderings when they have disappeared 
from our view. The only probable conjecture regarding it is 
that in their ordinary habits they only pass from the deeper 
water to the shore, to return to the former again immediately 
as the great duty of spawning is accomplished. On the whole, 
the general constancy of this fish to the British coast appears 
not the less worthy of notice, since we are informed that as 
regards Sweden and a portion of Denmark, they have long 
ceased to appear in districts where once they were known and 
welcomed; and although, if we could look back to a much 
greater distance of time, the visits may have been more 
unusual than the departure, yet in this respect also this alter- 
nation of habits bears a resemblance to what we have already 
noticed in the Pilchard. Thus we are told that in Loch 
Eoag, in the Island of Lewis, the scarcity or absence of the 
Herring and its abundance have taken turns at intervals of 
from thirty to forty years; and at Cromarty, says Mr. Mitchell, 
a very extensive fishery was carried on from 1690 to 1709, 
and in 1707 an immense shoal was thrown (or rather ran 
themselves) on shore in a little bay to the east of the town, 
so that the beach was covered with them to the depth of 
several feet; but, strange to say, they left the Firth in a single 
night, and no shoals again made their appearance for more 
than half a century. 
We have already said that without doubt a principal impulse 
which drives the Herring to our shores is the instinct of 
shedding its spawn; and it seems certain also that such 
individuals of these fishes as are in an equal degree of for- 
wardness in the preparation for this function, are collected 
into one company; in proof of which it was observed, that 
early in January, 1864, not far from Plymouth, all that were 
caught in drift-nets on one day, to a large amount would be 
shotten, while an equal number on the day before or after 
would be full of roe; and the fishermen had good reason to 
notice this, as the price of each capture differed considerably. 
I am informed that no Pilchards are found to be mingled 
with these assembled bodies of Herrings, although it is common 
to find Herrings among a collected body of Pilchards. 
