56 Ichthyology of the Firth of Forth. 
me to account for the number of small fry, two inches in length, that 
are found in the Firth of Forth during the month of July ; and the 
young herrings that are taken from six to seven inches long in the 
month of February, mixed with fry from two to three inches in 
length. When herrings are brought to the market in the first two 
months of the year, I have always found them full of spawn, and in 
the middle of March I have observed many very lank, with not a 
single ovum to be seen. Hence it is not improbable, that the same 
species of herring might spawn twice in the year, early in the month 
of March and also towards the end of October. 
Pennant supposes that the herring migrates to a considerable dis- 
tance ,- that they begin to appear first off the Shetland Islands in 
April and May, and divide into distinct columns from four to six 
miles in length and three to four in breadth ; and that after they 
have taken their circuit, they return again to the Arctic circle, where 
they recruit themselves after the fatigue of spawning. But it is 
more consistent to suppose, that the herrings approach our shores 
for the purpose of depositing their spawn like other fishes, and when 
this is accomplished, return again to the deep sea. 
The most common length of a full-grown herring is eleven inches, 
and two and a quarter deep. The upper part of the back is of a 
deep glossy blue ; the sides and belly silvery white. Each jaw on 
the anterior part is furnished with six or eight teeth placed in one 
row, which are more perceptible on the lower than on the upper jaw; 
the vomer is supplied with a double row, about sixteen in number ; 
on each side is another row of teeth, which are rather smaller ; the 
tongue is also armed with teeth, arranged in three or four rows, with 
their points directed inwards j the under jaw is longest, and is tipped 
with black ; eyes large and silvery, placed nearer to the point of the 
nose than to the posterior margin of the operculum. The first ray 
of the dorsal fin in an adult fish arises exactly halfway between the 
point of the upper jaw and the base of the middle caudal rays ; the 
origin of the ventral fins is placed behind the third dorsal ray, half 
way between the point of the lower jaw, and a little beyond the 
end of the middle caudal rays. 
The fin rays in number are : 
' D. 17 ; C. 20 ; P. 16 ; V. 9 ; A. 15 ; Vert. 56 ; Coecal append. 21. 
The tail is deeply forked, the middle rays less than half the 
length of the longest ray of the same fin ; the second ray of the dor- 
sal fin, a little longer than the base of that fin ; the scales are large, 
oval, and very deciduous, placed in fifteen rows between the dorsal 
and ventral fins. Most authors suppose, that the belly of the her- 
ring is not serrated in any stage of its growth, which is said to form 
