182 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



months and which had come from the " area of liberation," 

 tend now, either to remain where they were, or to move to 

 North and South, still remaining offshore and in water of much 

 the same depth. Note also a very interesting feature : the 

 water is warmer inshore and colder offshore, and it is still 

 rising in temperature, but it is rising more rapidly inshore than 

 it is rising offshore. 



The September Migrations. 



As before, the boundary line marked "August" shows 

 where the plaice caught in June- July, on the " area of 

 liberation," were in August. Only a very few fish were caught 

 in September on the latter area, but it will be seen that large 

 parts of the August region of recapture are also vacant. The 

 marked plaice are now evidently drawing in from the extensive 

 region mostly just outside the ten-fathom contour line and are 

 tending to move back inshore again. This is the plain meaning 

 of the chart. 



The October Migrations. 



Clearly the inshore retreating movements observed in 

 September continue during October. The boundary line 

 marked " September " surrounds the region where the marked 

 fish were in that month, and it will be seen that the inshore 

 migrations from the September region is very well indicated. 

 The " area of liberation " is now obviously invaded, but in 

 addition plaice are spreading both to the North and South. 

 There are two main trends in this North and South migration 

 which are more clearly shown in the November and December 

 recaptures. 



The November Migrations. 



There are now three distinct migration paths : — 



(1) Inshore directly to the " area of liberation " and to the 



other shallow-water grounds in the Bays and Estuaries 



(Morecambe Bay, the Mersey and Dee) 



