36 ANIMAL LIFE UNDER WATER 



tive salmon are lost in this manner, and much 

 of the keepers' work on the upper waters 

 wasted. 



I know it will be said that the smolts are 

 taken by congers and other predatory fish in the 

 sea. That is so; it emphasises the need to 

 remove those enemies of the young salmon 

 which can be readily dealt with. 



Before I can expect the reader to accept the 

 -theory that " flashes " from the diver attract 

 fish to it, it will be necessary to show that divers 

 in general "flash" in a similar manner. This 

 is not difficult, for not only do all divers " flash," 

 but the plumage of those divers that fish in dark, 

 deep waters are exceptionally arranged to simu- 

 late the flashings of fish. 



One of the best examples of this is to be 

 found in the great northern diver. This bird 

 remains under the water for several minutes at 

 a time. It dives deep, and can swim 150 to 200 

 yards before it comes up, though on occasions 

 it can greatly exceed this distance. 



This handsome bird is not uncommon in the 

 northern parts of our isles, but it is essentially 

 an Arctic bird, and fishes in sombre surround- 

 ings where there is insufficient light under the 



