of the Fishery Board for Scotland. 



225 



overlap in size, although many haddocks' eggs attain a size unknown to 

 the cod. Thus, ft is not surprising that Dannevig found the effect of 

 temperature on both species to be practically the same. This being so, 

 we should expect to find that the conditions of spawning of the two are 

 closely similar. This is borne out by the facts, at least in the Firth of 

 Forth area. We find that the extreme occurrence of haddocks' eggs 

 extends from February 8th to June 13th. In all the years but 1892 

 they were not found after the third week of April. The earliest occur- 

 rence of haddocks' eggs in 1892 was March 15th, or five weeks later than 

 in 1895. The year 1892, therefore, appears to have been marked by a 

 remarkedly late spawning-period for this species. 



The general occurrence is closely similar to that of the cod. With a 

 single exception (one egg), no eggs are found in the inner or middle 

 stations till March 19th, whereas abundance were found in Stations VIII. 

 and IX. Great numbers continue to occur up till April 24th, when a 

 sudden cessation ensues. The large masses can be distinctly traced 

 through Stations V., VI., and VII. into the inner part of the Firth, and 

 here they are still found at the hatching-stage at the end of April, in 

 some cases into May. The facts clearly point to the same conclusion 

 as in the case of the cod, namely, that the myriads of ova, starting 

 from Stations VIII. and IX., are, in great numbers, drifted into the 

 Firth, and are not spawned there. 



This is corroborated by the study of spawning adults. The main 

 difference between the spawning of the cod and that of the haddock 

 appears to be that the haddock seem to concentrate in certain areas to a 

 greater extent. The number of haddock's eggs found together usually 

 greatly exceeds that of the cod's, and this fact may be compared with the 

 statement that the spawning haddock were not caught more than 30 

 miles from land, whilst spawning cod were found at 170 miles from 

 shore. The more vagrant instinct of the cod may perhaps account for 

 the necessity, in the case of this species, of a far higher fecundity. 

 Fulton gives the spawning-period of the haddock on the East Coast as 

 from the second week of January to the middle of May. As in the case 

 of the cod, these limits extend in both directions beyond those of the 

 reported occurrence of pelagic ova in the Firth of Forth (with the excep- 

 tion of 1892). There is little evidence of extensive migrations in a 

 settled direction by the young haddock or young cod, though the migra- 

 tion seawards to the spawning-grounds, on the attainment of maturity, is 

 undeniable. 



With regard to the direction taken by the eggs and their subsequent 

 fate, the same remarks apply to the haddock as to the cod, and it is in 

 like manner probable that the Firth of Forth is dependent upon the 

 prevalence of east winds for its supplies of floating ova. Hatching 

 haddock's eggs can be found all over the Forth district. 



TABLE III. -EGGS OF WHITING. 



Firth of Forth. 



Station V., .... 



„ VI., ... 2. 



,, VII., ... 4. 



„ VIII. and XL, . 23. 



„ V., . . . . 1. 



„ VI., . . . 2. 



V 9 



v., . . . V. 



„ II., . . . . Eggs of. 



10 miles E. of May Island, . 90 (cod and whiting). 



8 to 12 miles E. of May 500 (cod and whiting). 

 Island, 



Feb. 22, 1894. 

 » 26, „ 



Mar. 19, ,, 

 „ 19, „ 

 m 20, „ 

 „ 26, „ 

 „ 29, „ 

 „ 30, 1891. 



April 4, 1893. 

 5, 1892. 



