RAPPORTS. XIII C2: THOMPSON 



— 8 



In the October to December curve (fig. 4) the 0-group indicates apparently a consider- 

 ably smaller size, namely about 1 1 centimetres, than it did in the July to September curve ; 

 we are now dealing with a very much larger number, about 1900, of these small mesh 

 fish, and the results are better and more representative. The gradual and evident increase 

 of size of the remaining groups, and the clear and unmistakable correspondence between 

 this curve and that of the preceding quarterly period are very well shown. It will be noticed 

 that the four-year-old fand older fish are now somewhat more numerous, their season of 

 comparative (though yet small) abundance being in the winter-time, while they are markedly 

 absent in the curves from April to September. 



10 20 30 40 50 60 70 80 90 100 110 



Fig. 6. Total number of Cod caught, at each centimetre of length, in the Moray Firth, 



during the quarterly period January — March (1903 — 1909). 



(2) The sizes of Cod in the Moray Firth. The curves (fig. 6—9) for the Moray 

 Firth are based upon a very much smaller aggregate number of fish, namely about 7,CXX) from 

 the otter trawl together with 2,6oo from the small mesh net; but nevertheless, the indi- 

 cations which they give are scarcely less clear than in the former case. Without going 

 into details regarding the rate of growth which they indicate, I may simply say that they 

 will be found to harmonise very fairly well with the Firth of Forth curves, so far as the 

 two are comparable. But these curves at once reveal a great and striking difference be- 

 tween the two regions; for whereas we found that in the Firth of Forth the older fishes, 

 or full-grown Cod, were extremely scarce, here in the Moray Firth, we find them present 

 in large numbers. For instance, in fig. 6, representing the Cod caught in the Moray Firth 



