IGNORANCE OF HABITS, ETC., OF HERRING. 17 



itself differs, the one part of it from another, in depth 

 and in saltness ; and consequently, to some extent, 

 in temperature, all of which affect the animal and 

 vegetable life subject to them. As to depth, the 

 North Sea may be divided into three zones : the 

 shallowest including the Dogger Bank, the coast 

 waters of Schleswig Holstein, and. Jutland, commu- 

 nicating with the ocean only through the narrow 

 British Channel ; the middle zone, extending from 

 the north of the Dogger Bank to a line drawn from 

 Peterhead in Scotland, to Cape Skagen in Jutland, 

 has a greater depth of water, receiving those brought 

 down by the Baltic, which are much less salt than 

 the ocean ; and the third zone, which is the deepest 

 of the three, stretching northward from Peterhead, 

 having a free communication with the Atlantic and 

 the cold water coming down from under the paleo- 

 crystic seas. The influence of the winds upon the 

 herring fishery is still an open question ; but it has 

 been found that under certain conditions, when a 

 coast is exposed to strong winds blowing towards it, 

 herrings will not approach ; that with a continuation 

 of stormy weather there is a very serious decrease 

 in the catch ; and that a violent gale precludes all 

 possibility of fishing* 



Under somewhat altered conditions a breeze may 

 be an advantage ; thus it is in evidence that at Peter- 

 head (Scotland), after a northerly breeze herring are 

 always to be had on that coast, and very heavy takes 

 have been made during thunder. 



The evidence collected by the late Frank Buckland; 



B 



