of the Fishery Board for Scotland. 



45 



The most certain way of proving this would be to dredge herring 

 spawn from one of the offshore banks in an advanced stage of develop- 

 ment. I have made several unsuccessful attempts to do this while 

 H.M.S. 'Jackal' was cruising some 40 miles north-east of Fraserburgh. 



Instead of continuing the attempt to dredge spawn from deep water 

 under unfavourable conditions, it occurred to me that it was possible to 

 practically settle the question at issue by depositing eggs in deep water, 

 so as to learn whether or not they would develop in the usual way. An 

 attempt to do this was made in 1884, but without success. In the 

 autumn of 1884 I was unable to join the 'Jackal' until the fishing 

 season was nearly at an end. However, after some difficulty, ripe herring 

 were obtained, and the artificially fertilised eggs deposited in the deep 

 water off Fraserburgh in wooden boxes specially constructed for the 

 purpose. Unfortunately a storm set in the day before it was arranged 

 to haul up the boxes, and although diligent search was made in all 

 directions in the vicinity of the 'Pot,' it was impossible to find any 

 trace of either the buoys or the hatching boxes. 



Owing to the Moray Firth being in many respects unsuitable for this 

 experiment, I turned my attention to the West Coast, and found a com- 

 paratively sheltered spot in Loch Fyne, with a depth of 104 fathoms. 

 To insure success, I had a small tank constructed of thick slate slabs 

 firmly bound together by iron rods. The tank, though only about 

 20 inches square, weighed nearly 2 cwts. In the top and in two sides of 

 this tank small windows were made about 6 inches square. Each window 

 was carefully fitted with a teak frame, across which a single layer of 

 horse-hair cloth was stretched. These windows admitted a sufficient 

 current of water to pass through the tank. All the necessary prepara- 

 tions having been made for depositing the tank during last autumn, we 

 were arranging to have eggs conveyed from the East Coast, when it was 

 discovered that herring were spawning in Loch Fyne. Mr Brook, who 

 was engaged at the Fishery Board Tarbert Station during the autumn, 

 kindly undertook, in my absence, to bbtain eggs and superintend the 

 sinking of the tank in the 100 fathom water. Eggs were obtained on the 

 1 1 th of September from herring caught in Kilbrannan Sound in water 

 varying from 8 to 12 fathoms. All the eggs were placed at first in the 

 laboratory in water, which had an average temperature of 54° Fahr. 

 Most of the eggs kept in the laboratory hatched out on the 19th, while 

 others only hatched on the 24th, thirteen days after fertilisation. 



On the 16th, one of the glass plates, coated with eggs, was introduced 

 into the tank above mentioned, which was immediately conveyed to the 

 middle of the channel and deposited in 98 fathoms water, about three 

 miles off Tarbert The rank was lowered by means of a strong manilla 

 rope, to the upper end of which a large cask was attached to serve as a 

 buoy. The surface temperature was 54° Fahr., the bottom temperature 

 was 49° Fahr. The bottom around the tank was chiefly composed of 

 mud. On the 24th — i.e., thirteen days after fertilisation, and eight days 

 after the eggs were deposited in 98 fathoms water — the tank was raised. 

 On examining the glass plate, it was found a number of the eggs in the 

 centre had been destroyed by a fine coating of mud, which had entered 

 through the hair-cloth screen, while those near the margins contained 

 vigorous embryoes almost ready to hatch ; in a few cases hatching had 

 taken place. The average bottom temperature while the eggs were 

 deposited was 49"3° Fahr.; the average surface temperature, 54° Fahr., 

 the difference being 4'7°. This is a much smaller difference than was 

 expected, and may be accounted for by warm bottom currents running 

 along the deep narrow channel which extends from opposite Tarbert 



