210 | 3 ZOOLOGY. 
America. They have never been seen to return to the north, and their 
migrations themselves occur neither at perfectly regular intervals. nor in 
the same direction. The density of the columns also varies much in 
different parts of the army. In some seasons the numbers are countless, in 
others very limited; at one time the individuals will be fat and large, at 
another very lean. By the end of August they are no longer seen. The 
Dutch, who, since 1164, have prosecuted the herring fishery with. the 
greatest success, sometimes employ whole fleets of boats in the pursuit. At 
no very remote period, the number of boats annually leaving the Texel, 
under the protection of vessels of war, amounted to not less than eleven or 
twelve hundred. This trade was at its highest state of prosperity in the 
year 1618, at which time the number of boats employed was 3000, manned 
by fifty to sixty thousand men. Since that time the trade has passed out 
of the hands of the Dutch, to a certain extent, and is carried on by many 
nations of northern Europe. According to Black, the fishermen of Gothen-, 
burg alone, in his time, took upwards of 700,000,000 herrings. More than 
130,000 barrels have been exported from Bergen in Norway; the amount 
consumed in the entire land exceeding double this number. At the present 
day, the largest quantities are taken on the shores of England. Recent 
investigations have rendered it probable that the herring actually does live 
within a moderate distance of the localities where it is caught, coming in ~ 
from the deep water for the sake of depositing its spawn. 
A beautiful spectacle is exhibited when the herring approach the shores ; 
the rays of the sun are reflected from myriads of silver scales, and above 
the army may be seen hovering hosts cf gulls, terns, and other sea birds. 
Behind and alongside are numerous rapacious fish, which, with seals, por- 
poises, and other marine animals, devour immense numbers. The water is 
filled with loose scales, rubbed off by their close proximity. On account of 
their vast numbers, these fish are very easily captured. This is done by 
means of nets, either on shore or at sea. Every Dutch smack has four 
smaller boats along with it, to carry fresh fish to the sea ports, and for other 
purposes. They use nets of 500 or 600 fathoms in length, made of coarse 
Persian silk, as being stronger than hemp. These are blackened by smoke, 
in order that the fish may not be frightened by the white thread. The nets 
are set in the evening, buoyed by empty barrels, and stretched by weights ; 
they thus rest at the surface of the sea. In the morning they are drawn 
in by means of a windlass. The herrings are sometimes attracted within 
reach of the nets by lanterns suspended at various intervals. Buta faint idea 
can be formed of the actual number of these prolific fishes, which exists at 
one time in the ocean. When we remember, however, that an annual 
consumption of over two thousand millions in Europe, not to mention the 
myriads devoured by fishes, birds, and various marine vertebrata, scarcely 
appears to affect their number, we may obtain an approximate conception 
of what that number must be to which the sum of those annually destroyed 
is in such small proportion. 
As the herrings are so abundant, and the flesh at the same time so excel- 
lent, various modes have been adopted to preserve them fora certain length 
414 ; 
