244 SALT-WATER FISHES 



themselves. Whiting, too, were for many years scarce in the 

 Lancashire district, * but were plentiful on the Aberystwith 

 part of the Welsh coast. It may, however, be desirable to 

 distinguish between regular migrations with the seasons and 

 what has more conveniently been termed " periodicity " — a habit 

 which makes certain fishes plentiful on a given part of the 

 coast at long and irregular periods, years often elapsing between 

 two seasons of plenty. The hake, to quote a member of the 

 family under notice, is in many parts regarded as a periodic 

 rather than as a migratory fish, its movements being also 

 largely dependent upon those of the smaller fishes, such as 

 herrings or pilchards, on which it feeds. In the Cattegat, 

 for instance, hakes were plentiful during the herring fishery 

 about the year 1780; then they were rare until 1801, when 

 they were once more plentiful until i8o3.t The next good 

 hake year in those northern waters was 1821 ; there was 

 another in 1830; and in 1840 the hake had almost dis- 

 appeared, though it has since been caught in quantity at 

 various times. 



On the question of whether the cod moves nearer shore 

 for spawning purposes or farther out to sea there appears to 

 be no agreement. Mr. Cunningham leans to the former view, 

 while Prof. Mcintosh favours the idea that they go seawards. 

 These two authorities, on the other hand, are both of 

 opinion that the whiting spawns in shallower water than the 

 larger fish, since the young are destroyed in thousands by 

 the shrimp-trawl. 



A number of the rarer deep-water members of the 

 cod family, some of which have been described and added 

 to the British fauna only within the last few years, and 

 the- majority with a wider distribution than the forms 

 inhabiting shallow water, will be noticed in the chapter on 



* See Herdman and Dawson, Fislics and Fislurus of the Irish Sea, 



P- 47- 



t Sec Samdinavian Fishes, p. 519. 



