— 40 - 



For comparison we give the average-number for each group and the average- 

 weights for the North Sea which D'Arcy Thompson has compiled from the 

 Aberdeen trawlers' statistics: — 



Average per trawl-hour 



Weight in kilos 

 Group Number As per Fig. 28 ^""""^ D'Arcy Thompson's 



St3.LlSllCS 



Extra Large ... 0-4 07 o-8 



Ivarge 3-0 2-5 30-1 



Medium 6-6 2-5 — 



Small 13-1 3-2 23-8 



Extra Small . . . 19-9 27 o-8 



Marketable total 43-0 ir-6 68-9 



Here we see that in the catches of the research steamers Extra Smalls and 

 Smalls constituted roughly half the weight of all the marketable haddocks. The 

 greatest weight we find under Smalls, though apart from Extra Large there is 

 no great difference between the weights for the different groups. It is worthy of 

 notice that the relation between Smalls and Large is as much as 4-4 when we 

 are considering numbers, whereas it is merely 1-3 if we take weights. 



A comparison between our figures and those of D'Arcy Thompson reveals 

 several points of interest. Of course in making the comparison we must keep in 

 mind that the weights cannot be compared by merely contrasting the actual 

 values, both because of the varying nature of the fishing and because his figures 

 depend mainly upon catches made in the more northerly parts of the North Sea. 



The first thing we notice is the difference in the quantities of Extra 

 Smalls. This is of course mainly due to the fact that the market-trawlers throw 

 away a large amount of fish belonging to this group, and practically all of them 

 if the boats are making long voyages from Aberdeen. D'Arcy Thompson even 

 informs us that the Scotch trawlers on their trips to Iceland throw ovorboard the 

 bulk of the fish that are not either Large or Extra Large. And accordingly, at 

 the market in Aberdeen it was only possible to find mentionable quantities of 

 Extra Smalls when the catches had been made near the Scotch east coast. This 

 group seems thus to constitute a considerable portion of the weight of our average 

 catches, in spite of its almost disappearing in the market statistics. The average 

 weight per individual for this group is about 0-13 kilos. 



Whereas we estimate that in our material Smalls constitute about one fourth of 

 the whole weight, the statistics of D'Arcy Thompson assign them a third: and this 

 notwithstanding that the fishermen throw so many small haddocks overboard. 

 D'Arcy Thompson's figures for the average catches of Smalls and Total Haddocks 

 (his Fig. 26 and 28) show that the former bear a smaller proportion to the latter in 

 the most southerly and westerly of his areas than they do in the other areas of 

 the North Sea. As the catches of the research steamers were chiefly made in 

 the southern portion, it is reasonable to suppose that his proportion is really 

 smaller there than it is in the areas where the Aberdeen trawlers make their 



