(/ the Fishery Board for Scotland. 
345 
land, and France.* At this conference a number of important practical 
and scientific questions were considered. ])r C. G. J. Petersen, of tbe 
Danish fishery department, contributed a paper on his ' Studies' k on the 
f Age and Growth of Fish, with some allied questions 1 (vide p. 349), and 
I)r L. Kolmodin gave the results of observations as to the most suitable 
depth to which herring drift-nets should be sunk under different circum- 
stances. He pointed out the importance of the temperature and the 
presence of pelagic food (Cladocera, Copepoda), and explained a new 
apparatus he had devised to determine the food and temperature. Fisher- 
men recognise as important the relations of current, wind, and light. 
AVith south and south-west winds the nets are usually set at a greater, 
depth than when the wind is east or north, and this is due to a change in 
the temperature of the water. Dr Kolmodin's apparatus has been used 
since 1887 at seven of the ten stations formed in Gothland for fishery 
observations, and the author states that the boats employing his apparatus 
have, on the whole, obtained better catches than the boats fishing without it. 
Fishery Inspector Landmark described the mode of marking salmon 
and sea-trout now used in Norway, and which consists in clamping a 
small silver plate to the posterior portion of the dorsal fin. Each plate 
is 10 mm. long by 4 mm. broad, and has a number stamped on it. Each 
end consists of a claw at right angles to the plate ; these are thrust 
through the fin, and the ends bent towards one another. Some interest- 
ing results as to rate of growth, frequency of spawning, &c, are given. 
Very few marked male salmon were recaptured. A discussion took place 
on this question : — f Has experience shown that herring curing accord- 
' ing to the Scotch method offers better results than the Norwegian 
1 method ; and, if so, is the establishment of the Scotch system of selection 
'and branding desirable? 5 No definite conclusion was reached; an 
objection to a system of branding was stated to be the periodical character 
of the Bohuslan herring fishery, especially when considered in connection 
with the greater cost of the Scotch system. 
Dr Heincke, whose important investigations on the herring are so 
well known, read a suggestive paper on the desirability of international 
co-operation in obtaining a more complete knowledge of the migrations of 
the herring. He proposed that a number of stations in the North Sea 
and Baltic should be selected in relation to the coasts of Norway, Sweden, 
Denmark, Germany, Holland, and possibly Finland, and then in England 
and Scotland. At each station collections of herrings of all ages should 
be made, with records of the spawning places, and specimens of the 
spawn ; and twice a month, during the herring fishing, fifty herrings 
should be taken without selection from the greatest catches, and records 
made of the sex, condition of the reproductive organs, contents of stomach, 
and amount of fatness. A certain number should be set apart for inves- 
tigation of the relations of body structure, according to Dr Heincke's 
method. Dr Heincke suggests that the directors of the central station 
in each country should form an international scientific herring commission 
for the study and elaboration of the results. 
In connection with the question of immature fish, the following was 
discussed : — ' How far, with regard to the preservation of the fish supply, 
' there ought to be established in the interests of the fish trade and of 
' consumers, general sizes for saleable fish ; and whether it is desirable and 
' practicable to make international regulations thereupon.' The London 
International Conference of 1890 was referred to, and quotations made 
from the addresses of Professor M'lntosh and others, and it was stated 
* ForJiandlingar vid forsta attmcinna Svenska Fiskerikotiferensen i Goteborg, 1891. 
Stockholm, 1892. 
