o/ the Fisher 1/ Hoard for Scotla'ad. 387 



(3|- inches), and the largest 148 mm. (5[g^ inches); in October the 

 smallest was 67 mm. (2|- inches), and the largest 174 mm. (6^ inches), 

 and they were caught in thousands. Much the same thing was observed 

 in the hauls in deep water off Aberdeen, and here these small whitings 

 were later in appearing than in the bay. 



The increase in the maximum size in successive hauls is explicable by 

 the growth of the fish in the interval ; but the gradually increasing 

 abundance of smaller and smaller Avhitings at the bottom and in the 

 inshore waters, as the season advances, is no doubt due to the circum- 

 stance that they abandon their pelagic habit to a greater and greater extent 

 as the upper layers of water become colder, and they then appear in 

 the bay and shallower inshore waters in great numbers. Later, during 

 winter, while still present in the bay, they to a large extent withdraw to 

 the deeper water offshore, where tlie temperature is somewhat higher. In 

 the deep water between the Shetlands and jN'orway very few young 

 whitings were caught on the bottom — the greatest number in a drag was 

 sixty, compared with thousands in Aberdeen Bay. This may be due to 

 a prolonged pelagic habit, or to spawning taking place for the most part 

 near the coast. In the latter case the distance traversed by the mature 

 whitings must be considerable. The question will no doubt be settled 

 when the upper layers of water are properly explored. 



The growth of the young whiting is very rapid. The spawning season 

 extends from the beginning of March to the end of June, or beginning of 

 July, with its maximum about the end of April, and, at the temperature 

 of the water at that time, the eggs will take about ten or twelve days to 

 hatch. The bulk of the larval whitings may thus be regarded as 

 beginning their independent pelagic life in the early part of May, at a 

 length of about 3-5 mm. (4- inch). By the end of the summer they have 

 grown thirty times longer, exceeding, on the average, four inches in 

 length. 



The ranges and averages derived from the measurements of the small 

 whitings caught are given in the Table below. 



In Aberdeen Bay the six whitings of this series caught on 31st July 

 had an average length of 112 mm., or 4^^ inches, a size much too large 

 for the date, owing to the absence of the smaller fishes. On 4th 

 September 557 ranged from 85 mm., or 3|- inches, to 148 mm., or 

 5{| inches, the average being 109-8 mm., or 4i% inches. On 10th 

 September the range was from 76 to 157 mm. and the mean length 

 110-4 mm. (4f inches). On 18th October the range was from 67 to 

 174 mm. and the average length 115-6 mm., or 4^ inches. On 29th 

 November the mean length was 136-7 mm., or 5|- inches, the largest 

 measuring 190 mm., or 7| inches. 



We thus see that from 4th September until 29th November, an interval 

 of 86 days, the young whiting (in 1901) apparently increased its length, 

 on the average, by 26-9 mm. (1^ inch). The largest measured, us stated, 

 about 190 mm. in November and 148 mm. on 4th September, which 

 shows a maximum increase in the 86 days of 42 mm., or li^ inches. 



[Table. 



