In tlie tables appended to this Report particulars, so far as ascertained, 

 are given for all the fish recaptured from each experiment, these particulars 

 showing the sex of the fish, its length on Uberation and recapture, the date of 

 recapture, the position of recapture, the depth of water, the method of fishing, 

 the port of landing, the condition of the reproductive organs, and the general 

 condition of the fish. 



The methods of fishing, by which the fish were recaptured, are shown in the 

 following table, arranged under months : — 



The total number recaptured was 3735, but the means of capture was not 

 ascertained in 136 cases. Of the remainder, 3599, the number taken by steam trawl 

 was 3067, or 85-2 per cent. ; by line, 268, or 7*2 per cent. ; by ground-nets {i.e. 

 " set-nets " for cod and plaice), 239, or 6-4 per cent. ; by herring drift-nets, 7 ; 

 by salmon bag-nets, 5 ; by flounder seine nets, 5 ; and by unspecified nets, 8. 

 It will be observed that the proportion of fish recaptured in the spring months 

 (February-April) was larger than in any other season of the year. 



The marked fish on recapture, in the great majority of cases, came into my 

 hands intact with the label attached, but in 135 cases only the label was received, 

 with particulars, as far as ascertained. In regard to 28 of the fish, the precise 

 date of capture was unknown. The place of capture could not be ascertained for 

 129, and in 90 instances, fish taken (by foreign trawlers, as a rule) and landed at 

 foreign ports, were described as having been caught simply in the " Moray Firth," 

 without the particular locality being specified. 



While many of the marked plaice returned were examined by myself, the majority 

 were measured and the condition of the reproductive organs noted by Dr. Thomas 

 Scott, at the Marine Laboratory, Bay of Nigg. I have also to thank Dr. H. C. 

 WilUamson for the examination of a number of them. The marking on board 

 was done mostly under the supervision of Dr. A. Bowman, the naturahst. 



Methods of Marking. 



In the early experiments, in April 1910, the old system of marking, as described 

 in my former Report {Op. cit. p. 137) was used, the mark consisting of a brass 

 numbered and lettered disc attached by silver wire to a bone button or disc below. 

 But in all the experiments after April 1910, the marks used consisted mostly of 

 two vulcanite discs (the upper, with the lettering and numbers) held together by 

 silver wire ; and partly of single vulcanite studs pushed through near the edge of 

 the fish and held by a rubber ring, after the method adopted by Professor Heincke. 

 The number of plaice marked by the old method in April 1910 was 183, and of 

 these only 29, or 15"8 per cent., were recaptured. In the whole of the experiments 

 in the years 1904-1909, 1203 plaice were marked with the brass-and-bone marks, 

 and of these 340, or 28-3 per cent., were recaptured. In the years 1910-1913, 



