of the Fishery Board for Scotland. 
Sail Fluke {Arnoglossus megastoma). 
A female of this species, with well-developed ovaries, was caught off 
the Firth of Forth on llth June. It was 18 inches in length, and 
weighed 1 lb. 12 oz. The ovaries were pale cream-coloured, almost white, 
and no large clear ova could be seen ; they were small, compared with the 
size of the fish. They weighed 897 grains. The upper ovary was 6 
inches in length, and weighed 510 grains ; the lower ovary was 5 
inches long, and weighed 387 grains. Five grains were taken, and on 
enumeration were found to contain 2456 eggs, so that the total in the 
ovaries would be 440,606. The diameter of most of the ova ranged from 
0-90 to 0-72 mm. 
The Plaice (Pleuronedes platessa). 
Of this species, five fully developed females were examined, all of 
them caught in January about 15 miles north-east of St Abb's Head. 
In the plaice the ovaries are very large when the fish is mature, and 
extend posteriorly to the root of the tail, both the dorsal and ventral 
surfaces of the fish showing marked tumidity from the vent backwards. 
In those examined, the dorsal or upper ovary was usually, but not 
always, longer than the ventral ; in four of the specimens it was 
heavier, in one case to the extent of an ounce; in the fifth it was 
equal in weight to the ventral ovary. The particulars of each specimen 
are as follows : — 
Length of 
Fish 
(in inches). 
Weight 
of 
Fish. 
Weight of 
Ovaries 
(in grains). 
Weight of 
part taken 
(in grains). 
Number of 
Ova 
counted. 
Total 
Number 
of Ova 
in Ovaries. 
1 
2 
3 
4 
5 
174 
3 lb. I oz. 
2 lb. 10 oz. 
4 lb. 3i oz. 
4 lb. Hi oz. 
3 lb. 124 oz. 
2743 
2962 
5870 
7545 
7000 
240 
240 
240 
240 
210 
19,555 
12,030 
19,915 
10,330 
9,695 
223,497 
148,470 
487,087 
324,749 
323,166 
22 
22i 
20i 
In a plaice just on the point of maturity the great mass of the ovaries 
is formed of eggs having a diameter of about 0*9 to 1 mm. In the ripe 
plaice these are interspersed with large clear mature ova, having a diameter 
of about 1*65 mm. If the roe is boiled and sliced, it will be found that the 
large eggs are scattered throughout the mass, but rather more crowded 
towards the centre and the anterior end. Ova of these tw^o sizes make up 
the ovary; eggs of an intermediate size are very rare, not more than one in 
a thousand; so that the expansion of the ova is extremely rapid. In the 
specimens examined No. 1 and No. 3 were composed entirely of eggs of 
the smaller size ; Nos. 2, 4, and 5 possessed eggs of the two sizes. Of a 
mass of ova squeezed from a ripe plaice, 180 grains contained 2590 large 
ova and only 39 small ; 60 grains removed from the surface contained 
183 large and 2830 small. The weight of the large clear ova is therefore 
about of a grain, and that of the small about -^^y or more than four 
times less. 
Buckland states* that in a fish weighing 5 lbs., the roe weighing 1 lb. 
9 oz., contained only 144,000 ova. It is not stated on what number of 
ova the calculation is based, and as the fish was captured at the end of 
May it is likely that it was partly spent. 
* Bejport on the Sea Fisheries of England and WaleSj pp. 199, 249, 1879. 
