SEA-FISHERIES LABORATORY. 215 



rather irregularly distributed points, but it seems certainly 

 to have the general shape represented. It rises more 

 quickly to a maximum about the end of July than it falls 

 away from this maximum. Superposed on it is a curve of 

 the variation of sea-temperature at the Liverpool North- 

 West Light Vessel in 1912, and it will be seen that the 

 variation in the value of the coefficient h is of the same 

 nature, and very much the same extent as that of the varia- 

 tion in sea temperature : in other words immature plaice 

 are in best condition when the sea temperature is higher 

 than when it is lower than the mean — a result which was, 

 of course, to be expected. 



c° 



K 

















Jb. 



■11 

















It- 











.■'is~ 



— -o ^ 







12- 



-1-0 









/J^ 

 S 



'^•"•"^-*> 







10- 



8- 



6 



■B^Mf 



.+. 



--r 





j/r' 









O 



'"" 





09 



















Jo.ny. 



Feby 



Mar 



X Afrit' 



May June July 



Aug Ser>r 



Oct. Now. Dec 





Fig. 5. Variation of the length-weight coefficient k, and of the Sea- 

 temperature. The unbroken line represents the variation of k, the 

 broken line that of Sea-temperature. O — points relate to temperature, 

 -f- — points to k 



The correspondence is not so close as it might have 

 been made if we had been able to obtain better series of 

 samples. The samples taken at the end of the year are 

 mainly those from the Eed Wharf Bay area, and here the 

 temperature of the sea is higher than it is at Liverpool 

 North- West Light Vessel. Also comparatively few 

 samples have been obtained during the early months of 

 the year : had there been more we should have obtained 

 lower values of k That is to say, if we could " weight " 

 ^-values, or the temperature values, so that each series 



