SEA-FISHERIES LABORATORY. 325 



presence of abundant bivalve food, even at considerable 

 distances, but the reason of these aggregations of plaice 

 on sea bottoms where there is for a time an abundant 

 young lamellibranch fauna is simply this, that plaice are 

 always to some extent moving about, except perhaps 

 during one or more of the colder winter months, and when 

 they encounter accidentally such an abundance of their 

 favourite food they remain in the place where this is to 

 be found deserting it when the food becomes scarce. 



On the other hand, the dab, being a greedier feeder, 

 and one accustomed to " take what it can get," finds a 

 more or less abundant table spread for it on almost any 

 of the shallow-water fishing grounds off our coasts. So 

 we find that the dab is much more widely distributed 

 than the plaice, and that when we cannot fish the latter 

 the dab is generally to be obtained. 



The sole is again more fastidious than either plaice 

 or dab. The stomachs of these fish caught on the " John 

 Fell " have been examined very often, but the results 

 are not tabulated. One finds, however, that it is com- 

 paratively rarely that soles have any food animals in 

 their stomachs other than Polychaete worms. In the 

 varying abundance of the latter we have then one of the 

 causes of the migrations of the sole. Of course, this is 

 not the only cause, but, no doubt, it is one of the most 

 important. 



Finally I give the records of the examination of the 

 stomachs of several cod caught during the early part of 

 the year. They shew little beyond what we already knov> , 

 viz., that the cod feeds largely on fish and Crustacea. 



