SEA-FISHERIES LABORATORY. 115 



times iii the year, we have two contradictory opinions, 

 each of which has been maintained by competent inves- 

 tigators. Heincke believes that there are two distinct 

 races, but the Scandinavian and Danish authorities 

 contradict this. 



In connection with this we have to decide whether the 

 herring spawns more than once in the same year. From 

 what is known of other fish one is led to decide in the 

 negative. Heincke* is of opinion that spawn lias never 

 been found twice in the same year on the same spawning 

 ground, which would be the case if the same herring 

 spawned twice in one year. 



Cunninghamt directly contradicts this since he says 

 that two spawning periods have undoubtedly been 

 observed in one year in the same neighbourhood. 



Matthews* also believes that herring spawn twice in the 

 same year. Tie believes that the herring that spawn off 

 Ballantrae in February and March, and those which 

 spawn olf Campbeltown in spring and then swim into 

 Loch Fyne in the summer as spent herring, become ripe 

 there, and spawn for the second time from August to the 

 end of October. 



If the difference between two successive spawning 

 periods is always one year, then obviously spring herring 

 will remain spring herring. 



There is still another view as to the interval between 

 two successive spawning periods. The Scandinavian^ and 



* Naturgeschi elite des Herings. Berlin, 1898. Text, p. 47. 



| The Natural History of the Marketable Marine Fishes of the 

 British Islands, p. 151. London, 1896. 



{Fourth Ann. Rep. Scot. Fish. Bd., p. 61. 



§Trybom. Sillundersokningar vid Sveriges Vestkust. Hosten 

 1888^ Berattelse till Kongl. Civildepartementet. Stockholm, 1889, 

 p. 12 ; and Smitt, Om sillrasernas betydelse. Bihang till K. Svenska 

 Vet. Akad. Handlingar, Band 14. Afd. IV, No. 12. Stockholm, 

 1888. p. 13, 



