56 



end of the school. The opposite condition characterises the dabs. 

 This is the law of distribution which I stated in 1905 — Report 

 for that year, page 31 — and tried to explain, Report for 1914, 

 and in the Inter. Rev. d. ges. Hydrob. u. Hydrogr., Bd. VI., 1914. 



Another point comes into view by a further inspection of 

 the Forth and the Moray Firth experiments of the Fishery Board 

 for Scotland. From the " Goldseeker " results, with reference 

 to the mid-Forth stations, it is at once apparent that the shore 

 plaice have only a partial relationship to them. The migration 

 appears to take place along the shore rather than outwards by 

 way of the deeper water of the Firth. Even if the deeper stations 

 at the mouth of the Firth be considered it is evident that the depart- 

 ure and return take place in relatively shallow water. This leads to 

 the conclusion that the immigration is from north to south, and 

 the emigration in the opposite direction. With this is correlated 

 the fact of the inshore manifestation of the migration in the warm 

 months of the year, and the deeper water maximum immediately 

 offshore. With increase in size the plaice tend to migrate not so 

 far into shallow water in the summer, and the evidence indicates 

 a later appearance of the migrants which do penetrate into 

 territorial waters. The result of such movements is plainly 

 indicated for the three parallel stations of Burghead Bay. (See 

 the above table.) It goes to show moreover that the autumn and 

 the winter maximum is due not only to a migration from the 

 inshore of the smaller plaice but also to the coincident inshore 

 migration of the larger plaice. 



It is thus clear that the inshore regions of maximum, such 

 as those of the Tay and Holy Island, are contrasted with regions 

 of minimum during the summer in deeper water, but this contrast 

 is naturally not so apparent in the intervening regions south of 

 the Forth and south Northumberland, which approach more to 

 the conditions outside. 



Along the east coast of Scotland and the north-east coast of 

 England plaice are arranged in groups, two of which are especially 

 here referred to, and there can be little doubt that each is related 

 to a spawning assemblage on the current side of the school. The 

 largest school is that of tho southern North Sea. From the 

 spawning grounds to the south of the Dogger, which are known 

 to be enormous, the eggs and larvae are carried towards the con 



