- 19 



LATER STAGES OF GADOIDS 



portion of large Haddock in A 3 may be very low, as it was in 1906, when the propor- 

 tion was 25.6 °/o, or it may be very high, as it was in 1909, when it attained to 90 °/o ; 

 but in all cases alike, it forms a focus in the distribution of large Haddock upon the map. 



In all cases the percentage in the areas off the east coast of Great Britain from north 

 to south was under 20°/o, and in the two years 1906 and 1910 we have regions with 

 less than 10% of large Haddock, both to the southward and to the northward. 



In spite of the marked variation from year to year, there is an underlying symmetry 

 in the distribution of large and small Haddock, which comes out very clearly in the means 



Fig. 32. Percentage af Large Haddock, 1909. 



Fig. 33. Percentage of Large Haddock, 1910. 



for the five years (fig. 34—35). It is certain, I think, that the normal distribution is suchthat 

 the proportion of small Haddock reaches its minimum and that of large Haddock its maximum 

 in the south-eastern corner of the North Sea. As we go east, and as we go north, the 

 percentage of small Haddock increases and that of large haddock diminishes. We have 

 in both cases a series of simple contours focussed about a point on the Jutland coast, 

 in the region of Horn Reef. 



In the case of Cod the changes trom year to year in the relative proportion of the 

 different sizes are still considerable, but not nearly so great as in the case of haddock. 

 The large Cod invariably show a minimum off the eastern counties of England, and a 

 maximum on the opposite, or Jutland, side, which latter is more or less continuous with 

 an extension towards the north, and a narrower, but perceptible one, along the southern 



