236 Part I11—Twenty-fourth Annual Report 
In my previous paper I showed that an extremely close relation 
existed between the changes of the temperature of the water and the 
abundance and migration of the gurnard, none of them entering the Firth 
of Forth until the temperature reached about 40°5° F. The average 
number of gurnards taken in that Firth per haul of the net in the various 
months of the year, and the mean bottom temperature, are as follows :— 
| Jan. | Feb. | Mar.| Apr. | May.|June.|July.| Aug.|Sept.| Oct. | Nov.} Dee. 
Gurnards, . 02} «04; +29) 11-1 | 44°2 | 30:2 | 24:0 | 21°6 | 18°9| 8-4) 11 2 
Temperature, | 42:2 | 40°6 | 40:0 | 42-2 | 45°6 | 47-6 | 50°8 | 53°5 | 53-3 | 51-4 | 48-1 | 44°8 
On the other hand, in the Moray Firth and the Firth of Clyde, where 
there is deep water, the gurnards moved out into the deeper water. Here 
are the similar details for the deep-water stations in the Moray Firth 
and for the Clyde :— 
Jan. | Feb. | Mar.| Apr. |May.|June.|July.| Aug.|Sept.| Oct. | Nov.| Dec. 
Moray Firth— 
Gurnards, . - - - — | 21:0} 19°2'| 23:1 | 37:3) = | 39:4) 296) — 
Temperature, | — - — | 45:5) 47:7 | 502) 52:1) - | 526/494) —- 
Clyde— 
Gurnards, . | 13:6} 0:0 | 26°5 | 22:2/186| - | 10°6 | 63:6) 11°8| 27 Re 31:1 
There are not complete observations in regard to the Clyde to enable 
the mean temperature to be given, but they show that in January at the 
deeper stations, where the gurnards were chiefly caught, the temperature 
is from 47-48 F., and in December it is about 6 F. higher than in the 
Firth of Forth at the same period. 
It is thus to be inferred, from what is known in regard to the relation 
between the temperature of the water and the growth of fishes, that the 
young gurnards do not cease growing in winter, but that, migrating to 
regions where the winter temperature is high, they continue to grow and 
are found to be larger in spring. The explanation is necessary to account 
for the different groups in the collections. 
In a number of Tables appended to this paper the collections of gur- 
nards have been tabulated in one-centimetre groups, but in many cases the 
limits of the groups are much better brought out by a ‘5cm. arrangement 
of the measurements, and some of these will now be given. 
I have arranged in the following Table the measurements of certain 
collections from Aberdeen Bay, the Firth of Forth, and the Dornoch Firth, 
in ‘dem, up to 34cm. The columns refer to the collections, as follows:— 
Col. I. Aberdeen Bay, Summary of July collections. 
as ie 5 Sy a September collections. 
eee WB é. a a October collections. 
55 IV. Dornoch Firth, Summary of November collections. 
- V. Burghead Bay, 4 September collections. 
» VI. Firth of Forth, i May collections. 
spe Velie Sy 53 July collections. 
