RAPPORTS. XIII C2: THOMPSON 



14 



large Cod to the Moray Firth in the first half of the year, yet we do here see something 

 of the same kind, though on a much smaller scale, and especially during the months 

 from April to September (fig. 12, 13). But such large Cod are conspicuous by their ab- 

 sence in the winter-time, from October to December. At this time of year then, both in 

 the Firths and off the East Coast of Scotland, the full grown Cod are comparatively 

 speaking very scarce. 



I have only a few curves to show for other fishing grounds. The next curve (fig. 15) 

 shows the catch of Cod from the Fair Isle during the months of July to September. The 

 curve is based on the small number of 227 fish, and is accordingly rough and irregular. 

 It would be nearly, or quite, useless for a determination of the rate of growth of the fish. 



10 20 30 W 50 60 70 80 



Fig. 14. The corresponding curve; October — December. 



90 



100 



for the cusps of the curves are blurred and irregular. But it at least shows this important 

 and striking fact that the fish present are for the most part from 35 to 90 centimetres in 

 length; in other words, they are fish from about two-and-a-half to four-and-a-half years 

 old, the very fish, for the most part, that were characteristically scanty in the Moray 

 Firth. 



In figure 16 we see a somewhat better curve (based on 677 fish) from the Witch Ground 

 for the months of April to June. Here it would seem to be the third year fish, of about 

 45 centimetres in length, that predominate, while fishes a year or two years older are also 

 fairly abundant. 



While the characteristic migration of Cod outwards and homewards again, as it is 

 shown us in the Moray Firth, is thus clearly established, — the fish leaving the Firth at 

 about 3 — 4 years old and returning again at the age of 5 or 6 years, — and while it is 

 so far correlated with the presence of the 3|and 4 and 5 years old fish in the deeper 



