964 
SCANDINAVIAN FISHES. 
so long as the geographical separation is maintained. 
The three Herring varieties adopted by Heincke (1. c.), 
which he called A, B , and C , are also distinct expres- 
sions of different ages. The development has started 
from C, the characters of which, as Heincke says, are 
a blending of those of A and B; and the last-mentioned 
variety represents that stage of development in which 
the dorsal and ventral tins have moved furthest for- 
ward, again to recede, in accordance with the above- 
mentioned rule for the development, to the position 
which they occupy in Heincke’s variety A. 
Such is the manner in which the distinctions ad- 
duced between different kinds of Herring may be ex- 
plained away. Practically expressed, the result is that 
no constant character has been discovered for the as- 
sumed varieties or races. It must, therefore, be assumed 
that the geographical separation is not marked enough 
to effect a complete severance of variety or race. The 
Herring is a migratory fish, no more restricted to fixed 
localities within its range than other such fishes. On 
endeavouring to find a centre for that range in the 
basin of the Atlantic, we arrive at a conclusion which 
in a certain degree recalls Andeksson’s antiquated 
theory. A line including the White Sea, the extreme 
north of Norway, Iceland, Southern Greenland, New- 
foundland, the west coast of Canada and of the North- 
ern States, and further south on the European side 
meeting the Bay of Biscay, forms the approximate limit 
of the Herring’s extension in the Atlantic. That the 
Herring besides is really an oceanic fish, is clearly 
shown by the fact that it attains its maximum size and 
its highest development of form in the ocean. The 
largest Herrings in the market come from Iceland, 
Norwegian Nordland, and Norwegian Finmark. Their 
average size (to the end of the caudal lobes) is 33 — 
37 cm. Exceptionally large specimens are indeed known 
from other localities. From England we are told of 
Herrings 39 and 43 cm. long; but the most trustworthy 
and the latest accounts in Day (1. c.) give 32 cm. 
as the maximum length. The Bohuslan Herring of the 
present day is also in general of the same size, though 
exceptions are mot unknown. We have mentioned above 
a Herring from Helso (Northern Bohuslan) which, though 
shrunk by the spirit in which it is preserved, measures 
42 cm. to the end of the caudal lobes. It is not ab- 
solutely impossible that such Herrings may be native 
to our waters; but exceptions make no rule, and it 
must be regarded as most probable that the Herring 
attains its highest development, and has the centre of 
its range, in more northern regions, in the North At- 
lantic between Iceland and Norway. It is, beyond 
doubt, from this source that the Herring-fisheries of 
the North Sea and Norway, as well as of Bohuslan, 
derive their fluctuating supply". 
The experience of many years teaches that the 
Herring comes to Southern Norway from the north- 
west. The Scotch Herring-fishery also begins yearly 
off the Shetland Islands and gradually extends further 
and further south. The Herring thus makes from the 
north an annual ascent of the plateau, offering a depth 
of at most 100 fathoms, on which Great Britain and 
Ireland are situated. If this plateau (see the map) were 
raised to the surface of the ocean, it would form an 
unbroken stretch of dry land between the said islands 
and the Continent from the Skaw south to about the 
middle of the Bay of Biscay. The west coast of the 
territory thus produced would coincide to the south 
with the present limit of the Herring’s range in this 
part of the Atlantic. Between this plateau and Nor- 
way, along the west coast of Southern Norway, runs 
the deep, so-called Norwegian Channel into the Skager 
Rack, its depth falling short of 200 fathoms from the 
neighbourhood of Bergen south to Lindesnas, i. e. out- 
side the region where the Norwegian fishery for Spring 
Herring is carried on. The channel is rather narrow 
off Lindesnas, but widens and grows deeper in the 
Skager Rack, so that between Arendal and the Skatv, 
somewhat nearer to Norway than to Denmark, there 
a This opinion I advanced in 1878, as an explanation of the revival that had just begun in the Bohuslan Herring-fishery and of 
the prospects for its continuance, of which the authorities were then very dubious. About 1870 the fishery for Spring Herrings on the 
south coast of Norway had begun to decline. In 1872 the Royal Museum had obtained quite typical Spring Herrings from Stromstad. Dur- 
ing the first years of the decade the Museum received from Bohuslan several pelagic species, Bonitos and other rovers of the open Atlantic, 
notorious as pursuers of the Herring. In 1856 too A. V. Malm had taken off Kalfsund Herring-fry 46 — 49 mm. long, which, as was then 
assumed, could not possibly be the young of the Grass Herring (a smaller kind, spawning in spring) that is always to be found on the coast of 
Bohuslan. It therefore seemed beyond dispute that the Great Herring had been present for several years in the North Cattegat and the Ska- 
ger Rack, without being directly observed in those waters, until a part of the Herring army penetrated, after they had spawned, into the 
island-belt. I found every reason to believe, as has since been confirmed, that a new so-called Herring-period had set in on the coast of 
Bohuslan, i. e. that the Herring had made its way from the North Sea into the Skager Rack, deserting for this locality its spawning-places 
off the south-west of Norway. 
