242 ANIMALS AT WORK AND PL A Y 



near the surface at all. A bucket of Atlantic water 

 is to the eye simply a vessel of transparent brine, 

 unfouled with weed, void of fish, and, in most cases, 

 not visibly infested with any form of floating marine 

 organisms. Yet at any moment shoals of fish number- 

 ing millions of individuals may elect to enter this 

 apparently foodless waste ; the herring shoals dis- 

 appear from the coast at intervals into the deep 

 Atlantic, and return in good condition, oily and 

 exuberant, and the whales find sufficient food to make 

 them the ' fattest ' creatures in creation. 



Many of the whales are carnivorous ; some, in- 

 cluding the ' right ' whale, have long been known 

 to live on small sea crustaceans, which were supposed 

 to be found in exceptional numbers in the Arctic 

 Seas. But the case of the typical ' shoal ' fish, such 

 as pilchards and herrings, offered special difficulties. 

 When caught near land they were often found to 

 have been living on sand-eels, roe, and small fish 

 and crabs. But in the greater number of cases the 

 contents of their stomachs were quite unrecognis- 

 able, and the immense size of the shoals increased 

 the difficulty of believing that on the migration 

 they could live on fish or on vegetable food. For 

 fish moving in a serried shoal extending for a square 

 mile, and perhaps 30 ft. deep, it would be im- 

 possible to find room to chase and capture smaller 



