SEA-FISHERIES LABORATORY. 129 
But we may note the following :— 
I. Eastern and Southern North Sea. (Extracted from 
Heincke’s tables 96 to 115). 
___ K, (keel-scales)—210 autumn and 254 spring fish. 
io = 00001 
Vertebrae—173 autumn and 250 spring fish. 
P— <-0000001. 
Here we should have no hesitation in saying that we 
are dealing with two distinct races. 
In this case these are the only two measurements which 
we can compare. As the autumn group contains a much 
larger proportion of fish under 100 mm. in length, the indices 
representing the relative positions of fins and length of head 
cannot be used, as these change greatly with age in fish up 
to about 100 mm. 
Unfortunately, in Heincke’s other groups, the numbers 
are too small to base any reliable conclusions upon. 
Thus in the case of his “ Friihjahrs- und Herbstheringe 
der westlichen Ostsee,” K, is given in 383 spring herring, 
but only in 82 autumn herring. This gives P <-000001. 
In the same group, the head-length is given for 114 spring 
and 79 autumn fish, and gives the same value for P. 
In the case of herring from the Belt and Sound, the 
numbers of fish are :—K,, 90 and 77; vertebrae, 69 and 59 ; 
head-length, 91 and 63. ‘The respective values for P are: 
0-5, 0-5, and 0-48. Here we have no grounds for dis- 
tinguishing between the two series. Thus, in the different 
sub-groups, Heincke’s figures give in one case, with fair numbers 
of fish, strong support to his distinction between autumn 
and spring fish. In two other cases, where the numbers are 
smaller, one supports his contention, the other contradicts it. 
We cannot lump together some of Heincke’s districts 
to increase the number of fish. If there is anything in his 
theory of local races we must deal with each district separately. 
