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APPENDIX—ECONOMIC. 
A.—Lire-History anp Hapstts. 
Spawning.—About the beginning of the year the 
reproductive organs of mature Plaice become ripe and 
spawning commences. Spawning—that is the complete 
extrusion of the contained ripe ova and spermatozoa, lasts 
over a considerable period on any one fishing ground. 
This is due to the fact that it requires some time for any 
one fish to extrude all its ova, and also to the considerable 
variation in the time of ripening of the reproductive 
organs among all the mature fish present on the spawning 
ground. The duration of this ‘‘ spawning season ” varies 
in the seas round the British Islands. In the Danish seas 
it begins in November, attains a maximum in January 
and February, and ends in April. In the North Sea on 
the Scottish side it lasts from the middle of January till 
the end of May, with the maximum at the beginning of 
March. In Loch Fyne in the Firth of Clyde in 1898 no 
Plaice eggs were found till the middle of February and 
none after June; the maximum number was found in 
April. In the Irish Sea the exact limits of the season 
have not been determined, but certainly it begins later 
than in the North Sea. ‘Che maximum period as deter- 
mined by the abundance of ripe female fish is at the end 
of March. 
From one quarter to half a million eggs are extruded 
by a single female Plaice during its spawning season, the 
average number on the various fishing grounds being 
about 300,000. This number of eggs is small when com- 
pared with that of many other flat and round fishes. 
Generally the larger the fish the greater the number of 
eggs yielded. It is evident that during the spawning 
