THE COD 



89 



50 fathoms ; and 2,900 tons (still mostly large cod) between 

 20 and 30 fathoms mostly off the Firth of Forth (C 1). 

 The actual figures are : 



Northern Grounds 

 F 1 area 

 D3 „ 

 CI „ 

 Dl ., 

 E „ 

 D2 „ 

 G 



Tons. Southern Grounds. 



1,962 A area 



187 B 1 „ 



2,882 B 2 „ 



6,921 B 3 „ 



2,983 B 4 „ 



955 B 5 „ 



1 C2 „ 



C3 „ 



Total . . . 15,891^ Total 



Undistinguished, 4,840 tons. 



The distribution of the catch among v 



Steam trawlers caught 

 Steam liners 

 Sailing trawlers . 

 Sailing liners 

 Inshore fishermen 



Tons. 

 270 



5,204 



4,137 

 958 

 681 

 174 



9,761 

 486 



21,671 



was as follows 



Tons. 



124,477 



4,425 



854 



516 



2,062 



132,333 



Life-History 



In the hatchery at Woodshole, U.S.A., 9,168 fish were penned 

 in three years, and allowed to spawn naturally. They gave 

 815,000,000 eggs— an average of 111,000 per female, if it is 

 assumed that there was one male to every four females.^ Very 

 large ' hens ' are, of course, not used for breeding purposes in the 

 hatcheries — and large hens will no doubt produce more eggs, 

 though the eggs and milt of old fish are not so good as those of 

 younger ones. But the ' good and bad hatching years ' are 

 well marked, and the yield varies greatly from year to year. 

 97 per cent, of the eggs taken in hatcheries are impregnated. 

 The Americans believe that there is a heavy loss in nature 

 through failure of impregnation. Unfertihzed eggs are seldom 

 found at sea, but experiment in America has shown that they 

 sink after floating from eighteen to thirty-six hours at most. 

 The fertihzed eggs float— at the surface— if the density of the 

 water is sufficient, and hatch out according to the table below. 

 The eggs"are about one-eighteenth of an inch ^ in diameter on the 

 average. ' That is to say, about 406,000 of them are contained 

 in a fluid quart. ■* 



^ These figures omit the large catch by Scottish vessels in these waters. 



2 But it is probable from hatchery experience that not more than one-third 

 of these hens actually yielded good eggs, in which case the number would be 

 about 330,000 per fish. ^ -055 inches or 1-386 mm. 



* This and similar statements with regard to the number of eggs contained 

 in a quart are based on the table of H. von Bayer, Bull. U.S.B.F. xxviii, 

 p. 1013 ; see below, Appendix III, p. 206. 



