FISHERY RESEARCH 



323 



spawning grounds of the herring, since its eggs are laid 

 on the bottom. In this case, besides gaining information 

 from the actual catches of herring, an examination of the 

 stomach contents of other fish becomes advantageous. 

 It is known that the haddock will greedily devour herrings' 

 eggs, and the occurrence in the trawl of so-called " spawny 



Fig. 61. — Chart showing distribution of plaice eggs in the North Sea in December, 

 1910. The figures show the numbers of eggs per square metre surface. (After 



Buchanan-Wollaston.) 



haddock " crammed with herring spawn is a sure indication 



that the spawning grounds are not far off. An actual 



search for the eggs is far less fruitful, owing to the fact 



that they lie in the crevices between stones and are rarely 



taken in the trawl. On occasion they have been searched 



Y 



