37 



All the here mentioned breeding-grounds, found by us, evideutly be- 

 longed to the race of herrings called spring-herrings, of which Heincke states 

 that it breeds from March till June. He writes about this race in "Die 

 Fische der Ostsee. IV Bericht d. Comm. z. wiss. Unters. d. deut. Meere. p. 

 137'', that it "geht aber zum Laichen stets in brachische Buehten (Schlei, 

 Dassower Binnensee) oder in Ausweitungen der Flussmundingén(Schwentine)." 

 This is correct perhaps with respect to the Baltic Sea, but not with respect 

 to the Great Belt and the Limfjord. In the latter, in Nissum Bredning, the 

 water generally contains more than 3 p. c. salt, and can in no way therefore 

 be called brackish; and the Great Belt is neither a bay nor the mouth of 

 a river. 



Once only have I found the spawn of autumn -herrings deposited on 

 the bottom, viz. the 4th of August 1898, at Vresen (Nyborg), on algce and 

 zostera, between 4 and 8 fathoms of water, at the very same spot then 

 where also the spring-herring breeds. 



To get a survey of the breeding-grounds of the hemng in Denmark, 

 we must find many more of them. Perhaps they will come by and by of 

 their own accord. Contrary to the pelagic (floating) eggs, these are far more 

 difficult to point out. It is rather lucky finds and accidental circumstances 

 that lead to the discovery of the breeding-grounds. 



