PROPAGATION AND GROWTH OF HERRING. 643 



do not finish their spawning in spring, are found early in autumn with 

 strongly developed sexual organs, and therefore spawn somewhat earlier 

 than the other herrings of the same age. It is chiefly these herrings, 

 besides the older and larger ones, which also spawn somewhat earlier on 

 the outer coast, and which, therefore, are not so frequently caught in 

 nets, which have given rise to the assertion that autumn or winter 

 spawning herrings occur on the coast of Bohusliin.^^ The sexual organs 

 of the herring develop much slower during winter when food is not so 

 plentiful ; for this reason the spring-spawning herrings have their sexual 

 organs developed much longer before the spawning-time than is the case 

 with the autumn-spawning herrings. Whenever, therefore, herrings 

 are observed during autumn with well-developed, firm and hard roe or 

 milt, this is a sure indication that the herrrings will soon commence to 

 spawn. The erroneous oiiinion, which in a similar case has been ad- 

 vanced by Strom, Malberg, Lybecker, Mlsso7i, Kroyer, Loberg, Axel Boec7{:, 

 and others, concerning the spawning of the Norwegian summer and 

 autumn herring ^i, should be a warning example against hasty opinions 

 based on insufficient observations or data regarding the spawning-sea- 

 son of the herring.^'^ It is also well known from olden times that the 

 different age of the herrings has an influence on the varyisg spawning- 

 season.^^ Nilsson thus reports that the young herrings at Skelderviken 

 and the coast of North Holland spawn sooner than the old herrings,^* 

 whilst in the Sound the old herrings, according to Winther, spawn 

 sooner.^^ It seems that those herrings which spawn during winter and 

 spring are, in this respect, the very reverse of those which spawn towards 

 the end of summer and during autumn. 



The spawning-time of our Bohusliin coast herrings seems to have re- 

 mained the same, at least as far as can be judged with any degree of 

 certainty from the more or less distinct notices regarding these fisheries 

 in the " Trangrums-acten''^ (law regarding the refuse from train-oil refine- 

 ries), in the reports of Mr. Clancey, superintendent of herring-fisheries in 



20 See my " Preliminar beriittelse for 1874-'75," pp. 10-12. 



21 H. Strom, " Physisk og (economist Beskrivelse over Fogderiet Sondnwr." I. Soro, 1762, 

 p. 303. — C. R. MOLBERG, ''Afhandling om Salivandsfiskerierne i Norge" (Kgl. dauske 

 Landhunsliolduings-Selskabs Skrifter, iii, Copenliagen, 1790), p. 370. — I. L. Lybecker, 

 " OmFiskeneog Fiskerierne; AlmitidcUghed samt om Silde-Fiskerie7'>ie i Sardeleshed," Copen- 

 hagen, 1792, p. 82. — Nilsson, " Skandinavisk Fauna," iv, pp. 496,511. — Kroyer, ^^ Dan- 

 marks Fiske," iii, p. 170. — O. N. Loberg, " Xorges Fiskerier," Christiania, 1864, p. 93. — 

 BoECK, '' Om Sildcn og Sildefiskerierne," p. 122. — See, also, G. O. Sars, " Indberetrdng 

 om de i Aarene 1870-'73, anstillede praktisk-videnskahelige Under sogelser" Christiania, 

 1874, p, 37. 



2^ Nearly all similar opinions regarding the spawning-time of the herring and the 

 small-herring are also based on the erroneous idea that aU successful herring-fisheries 

 must necessarily be spawning-herring fisheries. 



23 See M. E. Block, " Oeconomische Naturgeschichte der Fishce Deutschlands." I. Berlin, 

 1782, p. 191. 



2* Handlingar rorande sUlfisket, pp. 56, 58, 60. 



^^Nordiah Tidsskrift for Fiskeri, iii, p. 12. 



