238 On the Lift-history 0/ Gobi us minufus. 



certainty from the above data is that 32-36 mm. is the limit 

 of growth for the first season in G. flavescens. 



Holt and Byrne give 64 mm. as the total length of a 

 fully grown specimen of this species. The largest specimens 

 in the collections under consideration only measure 42 and 

 44'5 mm. respectively. The former was captured on Smith 

 Bank on 25/7/90, the latter on 28/5/96, "locality not stated. 

 It seems probable that larger examples of this species may 

 exist off the east coast of Scotland, for a form 44*5 mm. at the 

 end of May would doubtless attain a greater length before 

 the close of the season. At all events it seems probable that 

 maturity is reached during the spring or summer following 

 the season in which the fishes were hatched. An interesting 

 account of the life-history and habits of this species is given 

 by Holt and Byrne *, from which the following paragraph is 

 quoted: — u So far as any conclusions can be drawn from 

 merely examining specimens of a species with such an ex- 

 tended breeding-season, it appears that members of this 

 species do not ordinarily survive the second winter following 

 ihe summer in which they are hatched." It is this " extended 

 breeding-season " which renders equally problematical the 

 rate of growth in G. flavescens. Reasons have been stated 

 for taking April as the earliest month of spawning, and 34 mm. 

 as the greatest average length attained at the close of the first 

 season — that is, about the end of October. Supposing that 

 the young forms are hatched at the end of April, and that 

 they measure 1 mm. on hatching, the average rate of growth 

 during the first season may be given approximately as ^r- 1 

 or 5*5 mm. per month. The data are insufficient to offer 

 even an approximation to the rate of growth for the second 

 season. For instance, a specimen in the second season 

 measures 44*5 mm. at the end of May ; it may be asked, Is 

 this one of the forms which reaches over 30 mm. in the pre- 

 ceding autumn, or one of those which only measures 10 mm. 

 at the same period? The answer to such a question must 

 be doubtful. To render the first case probable it is necessary 

 to assume that there is in this species a winter rest of con- 

 siderable duration ; the second case would indicate that the 

 rate of growth was little influenced by seasonal changes. 



Dr. J. R. Tosh, in the notes which have been referred to, 

 makes the following observation: — "The young are without 

 the second spot below the first dorsal fin up to about 28 mm. 

 From 30-32 mm. it begins to show faintly, and thereafter it 

 increases in density. The spot shows well in forms 35- 



* Irish Fisheries Reports, 1901, part ii. p. 50, 



