THE FEEDING OF SALMON 117 



sand-eels and herrings in the stomachs, and reports 

 that Jardine states that salmon are often taken on 

 the coast of Sutherland, on haddock lines baited 

 with sand-eels. Other observers have made similar 

 reports. Even in fish shops where sea-caught 

 salmon are sold, after being cut across, one may 

 sometimes notice that herring had been the food 

 last taken. 



There is, then, a great contrast between the con- 

 dition of the stomach and intestines of fish caught 

 in the sea and the condition observed in fish caught 

 in rivers. In the former case the stomach is com- 

 monly found full of herriug or sand-eel food, the 

 intestines being correspondingly filled with ffecal 

 matter, while in the latter both stomach and 

 intestines are empty. We have, therefore, well- 

 defined periods in the life of the fish, and long 

 intervals during which no food is taken. 



One of the main objects of the investigations 

 undertaken by Dr. Noel Paton and his colleagues 

 was to determine whether salmon in fresh water 

 require food, and in the event of corroboration of 

 the results obtained by the Continental physiologists, 

 to study the changes which must necessarily take 

 place owing to the growth of the genitalia during a 

 period of starvation. In the female salmon the 

 growth of the reproductive organs is very great. 

 It has been ascertained that in April and May the 

 ovaries constitute about 1'2 per cent, of the weight 

 of the fish, while at the spawning season they repre- 

 sent as much as 23*3 per cent. In the male fish, 

 the actual increase is not in so great a proportion ' 



