958 
SCANDINAVIAN FISHES. 
tionally 24 — 32) from the isthmus to the ventral tins, 
and 13 — 15 (exceptionally 11 — 20) between these tins 
and the vent, in all 36 — 48. Just in front of the ven- 
tral tins lies a double plate, the upward processes being 
bifid, or shoAving indications that they Avere originally 
composed of as many as three processes. The other 
preabdominal plates, on the other hand, Avith the ex- 
ception of the foremost ones, are distinguished from those 
of the folloAving species by their long lateral processes. 
The colour of the back is steel-blue Avith a lustre 
of green and gold; the sides are silvery. The limit be- 
tween the colours of the back and belly is often marked 
by a tinge of lustrous green. The neAv-caught Herring 
glitters with a Avealth of hues, and in the darkness it 
gleams Avith phosphorescent light. The snout and the 
upper parts of the head, as Avell as the superior part of 
the opercular margin, are sometimes pure black. The 
Fig. 240. Spiniferous scales from the ventral margin of a Vlupea 
harengus 25 cm. long. Twice the natural size. 
a, the foremost spiniferous scale; b, the fifth, counting forward from 
the ventral fins; c, the double scale just in front of the ventral fins; 
d, the fifth scale, counting forward from the vent; e, the hindmost 
spiniferous scale. 
gill-covers are of a golden lustre, more and more suf- 
fused Avith blood, the longer the fish has been dead. 
The ventral and anal tins are Avhite but transparent, as 
Avell as the pectorals; but the upper margin of the last- 
mentioned tins is of a grayish or greenish black, which 
colour extends, in greater or less intensity, some Avay 
doAvn the fins. The dorsal and caudal tins are darker, 
though the membrane is transparent, more densely speck- 
led Avith grayish black, shading on the rays into green. 
The iris is sometimes silvery Avith a brassy lustre; in 
other cases the latter colour is predominant. 
With coloration of a lighter or darker tone, and Avith 
body more or less transparent, though this transparency 
is ahvays faint, the Herring varies according to the 
greater or less intensity of light in its surroundings. 
In the temperament of the whole Herring family 
gregariousness and a love of migration are the most pro- 
minent traits. The common Herring, an inhabitant of 
the North Atlantic and probably, as we have mentioned 
above, of the corresponding regions in the Pacific, roves 
in huge shoals Avithin the said geographical range. Hoav 
far its wanderings extend, is still an undecided question, 
though numerous investigators, from the beginning of 
the last century until iioav, have devoted their attention 
to its solution. In an Atlas maritimus commercialism 
printed in London in 1728, reference is made to the 
annual course of the Herring-fishery off the coasts of 
Great Britain and Ireland, then essentially the same as 
it is to the present day. The most important fishery 
in those Avaters begins in summer to the extreme north, 
off the Shetland Islands and then on the Scotch coast, 
but afterAvards advances further and further south on 
both sides of Great Britain, to England, Ireland, and 
the Channel. Hence it Avas inferred that the Herring- 
shoals must come from the far North; they Avere sup- 
posed at first to be so large and densely packed that 
they had difficulty in forcing a passage “betAveen the 
coasts of Greenland and North Cape”; but the Herring 
“army” divided as it came further south. On these as- 
sumptions the learned and clever Burgomaster of Ham- 
burg, Johan Andersson, d. 1743“, based his theory of 
the annual migrations of the Herring. The Herring, he 
opined, had its true home under the ice of the Arctic 
Circle. There lay its cradle, and thither it retreated 
year after year to escape its merciless pursuers, and to 
recruit its thinned numbers. But soon the home became 
overcroAvded; large multitudes Avere yearly compelled to 
emigrate southwards, and to divide into separate armies, 
Avhich marched partly to the right, to America, and 
partly to the left, to the Avest coast of Europe and into 
the Baltic. This theory Avas still accepted in the days 
of Pennant 6 ; but Bloch 6 ' and Noel' 6 shoAved it to be 
a See his Nachrichten von Island , Gronland und tier Strasse Davis, Hamburg 1746, pp. 51 — 72. 
b Brit. Zoology , 17 76. 
c Fische Deutschl., part. 1, p. 189. 
d Magazin Encyciopedique, tome VI, p. 5 (Paris 1795). 
