260 THE VARIATION, RACES AND MIGRATIONS OF THE MACKEREL. 



Table V., showing frequencies of values of jjartial Series of Bars. 



(Percentages.) 



We see from this table that the combined percentages in the two 

 right-hand columns exceed those in the two left-hand columns in only- 

 two cases, viz., Newport, and Brest and Scilly. This preponderance of 

 high values over low values corresponds to an excess of the mean 

 values above 18'5. 



In all other cases the figures in the two left-hand columns exceed 

 those in the two right-hand columns. This preponderance of low 

 values corresponds to mean-values less than 18*5. 



The figures for the North Sea and Plymouth again correspond with 

 remarkable exactitude, as also do those for Kinsale and Kerry. The 

 difference between the Irish values and those for the groups from the 

 North Sea and Channel is not great, but it is distinctly greater than 

 the difference between the North Sea and Plyoiouth groups i7iter se, or 

 between the groups from Kinsale and Kerry. The column which 

 contains the highest percentages for each of these four localities is 

 that recording the frequency of the numbers 17-18; and it will be 

 seen that while the frequency of these values varies from 46 °/o to 

 49 7o for the North Sea and Plymouth, it does not exceed 45 % for 

 Kinsale and Kerry. 



In this connexion it should be noticed that both the minimum and 

 maximum frequencies of the lowest values (12-16) are lower for the 

 Irish groups than for the North Sea and Plymouth. On the other 

 hand, the highest values of all (21-25) occur twice as often among 

 Kinsale and Kerry fish as among North Sea and Channel fish, viz., 8 7o. 

 as compared with 4% or 5%. This contrast in regard to the dis- 

 tribution of high and low values can be looked at in another way, viz., 

 by comparing the relative frequency of the highest and lowest values 

 in each group of fish. Thus in the American fish the frequency of the 

 highest values is more than twice as great as that of the lowest values 

 (16:7); for Brest and Scilly it is barely in e.xcess (7; 6); for Kinsale 



