Early Life-history of the Herring. 



369 



I do not propose to enter here into any minute structural 

 details. 



As is well known, all herrings do not spawn at the same 

 time, some selecting the spring and others the autumn for 

 that purpose. Professor M'Intosh is of opinion that by far 

 tlie greater number spawn in the spring ; and this seems con- 

 firmed, so far as regards this locality, by the greater abun- 

 dance of young forms obtained here in that season. 



Mr. Brook (' Fourtli Annual Report Scotch Fishery 

 Board ') gives January to March as the spring spawning- 

 season, the time varying with the locality, Anstruther and 

 Buckie being the earliest. 



The e,^g of the herring is demersal, differing thus from the 

 pelagic QQ^ of the sprat. The intraovarian development of 

 the herring has been worked out by Kupffer and subsequently 

 by Brook (3rd and 4th Ann. liep. S. F. B.). 



Eggs were obtained here on Feb. 5, 1S85, from Anstruther, 

 and hatched out in the laboratory in twenty-five days. 



Newly hatched forms occurred on March 7, 1887, and 

 larval and post-larval forms in March and the beginning of 

 April in 1887 and 1889. 



The period of incubation varies with the temperature *. 

 It is probably never less than three weeks in the early spring, 

 but it may be barely a week in the autumn. Thus, except iu 

 very early localities, young herrings cannot be expected before 

 the beginning of March. In 1889 great numbers of young- 

 herrings were obtained, the first being early postlarval forms 

 on Marcli 22 and larval and postlarval on Marcli 28. 



The newly hatched herring (figure 1), about ^r inch, longf.,^ 



Fio-. 1. 



is in the larval condition \, i. e. the yolk is still unabsorbed. 

 The absorption of the yolk takes three or four days, when the 



* See Mr. Brook's account of Meyer's experiments with regard to tem- 

 perature, ']rd Annual Report Fisliery Board for Scotland, 1884, p. 49, 



t Kupffer gives the length of the newly hatcliud Baltic herring at 5-2- 

 5-;3 millim. (3rd Ann. Rep. S. F. B, 1884, p. 47). 



\ Mr. J. T. Cunningham gives a figure of a larval herring in Trans. R. 

 S. E. vol. xxxiii. pt, 1. It dilleri sliglitly li'om my own figure. 



