232 Part IIT—Twenty-fourth Annual Report 
As I pointed out in my previous papers, these very young whitings 
have been leading a pelagic life, and now descend to the bottom when the 
seasonal change of temperature makes the water there warmer than the 
surface layers. 
Most of the fishes in this series were aggregated between 10cm. and 
l6cm., the apex being at 13cm., as well as the mean, and the arithmetic 
average was 132mm., or nearly 5} inches. The grouping of the larger 
whitings is not very clear, but most of them measured from 21cm. to 
30cm., the mean being about 25:5cm., or 10 inches, a difference of about 
12-5cem., or about 43 inches from the average of the younger group. 
In a collection made on 29th December, 1903, 498 whitings were 
obtained, nearly all belonging to the first group. ‘Their sizes ranged from 
115mm. to 180mm.; most were between 12cm. and l6cm., the greater 
number, or the apex of the curve, being 14cm. (53 inches), which was also 
the mean. 
The principal results in regard to the growth of the first group may be 
tabulated as follows :— 
Date. Average Size. | Smallest Size. | Largest Size. 
€m. |Inches} Cm. jInches|) Cm. _ |Inches 
Dornoch Firth, | 22nd October, . 11 43 5] 2 176 73 
Do., . . . | 11th November, 12 43 58 24 | 19-4 78 
Dor see Ae 2atheDecember: 13 5t 8°5 38 | 211 34 
Do, . . . | 7th December, 3°5 5355 | 
Burghead, . | 20th October, . 10°5 4t 75 3 Bie Me esc 53 
Do., . . . | 14th November 12 4: 81 dt | 17°4 6% 
Do... . . | 28th December, 3 54 ( 3 18°5 7k 
Off Kinnaird, . | 23rd January, . 12 43 7'6 3 16°5 64 
Smith Bank, . | 23rd October, . 12:3 43 8°7 34 16:0 62 
Aberdeen Bay, | 11th February,| 13 5h 761 Ines? 23] 
Do., =... 229th) March; | ©. 14 53 100.) 43-4) 
Do., | 3lst October, . 13 54 56 | 24 18-1 it 
Do., . . | 29th December, 14 54 115 | «43 18:0 7k 
‘The mean sizes of the second group of whitings varied as follows :— 
Burghead—20th October, 23°5cm., or 97 inches; 14th November, 27:5cm., 
or 103 inches. Smith Bank—Ist April, 24'5cm., or 93 inches, Aber- 
deen Bay—13th May, 22°5cm., or 8% inches ; 31st October, 22:5em., or 
10 inches. 
GREY OR COMMON GURNARD (Trigla gurnardus). 
The number of specimens of the grey gurnard measured in connection 
with the observations in this paper was 5495, belonging to about 50 
collections. 
Another paper in which the growth of this fish is dealt with was 
published in the Seventeenth Annual Report.* 
The spawning period of the gurnard is prolonged, extending from April 
to the latter part of August, and into September, or, according to Heincke 
and Ehrenbaum, to October; spawning is at its height in the early part 
of June. In May the duration of ‘‘incubation” is eight or ten days, but in 
*«On the Migratory Movements and Rate of Growth of the Grey or Common 
Gurnard,” Part III., p. 210. 
