of the Fishery Board for Scotland. 127 



inches in depth. It was kept nearly full of water, and was surrounded by a 

 jacket of ice. The water entered at the surface and escaped from the 

 bottom. The quantity of water passed through the box was 1 gallon (4| 

 litres) in 32 minutes. The bottom of the box was covered with sand. 

 In the first case the smaller fish was confined in the tin for three days. On 

 the first day the temperature fell from 7° to 3°C. Next day the temperature 

 at noon was 1-2°, on the third day the temperature varied from 1'7° to 

 — 6°, and on the fourth day up till 4 p.m. the temperature was from 

 '6 to — 1-2°C. It was alive on the third day at 4 p.m., at which time 

 the water was at — •1°C. On the following day at 11 a.m. tlie fish 

 seemed dead. IS^o breathing action was made out, but its body was soft ; 

 it was not in rigor. During the day, however, it did not shift its position. 

 When examined next day it was clearly dead : there was some slime 

 on the gills. Shelled mussels had been supplied to the fish, but it had 

 eaten none. 



The second turbot was put into water of 12'4°C. at 11 a.m., and the 

 cooling process was then commenced. At 1 p.m. the temperature had fallen 

 to 4 '6°. The fish was not breathing strongly. At 8 p.m. the water registered 

 3'3°. On the second day up till 8 p.m. the water had varied in temperature 

 from 3"4° to 1"7°. The turbot was alive, but during the day I was not 

 able to detect, through the water, any movement of the gill-cover. It 

 appears that the cold paralyses the muscles and breathing apparatus. If 

 continued too long the fish will probably die through asphyxiation. On 

 the third day at 10 a.m the temperature of the water had risen to 7°. 

 From the previous night the temperature had ranged from 2 '3° to 7°. The 

 turbot was alive. K"o food had up till now been offered the fish. Two 

 pieces of mussel were now put into the box. The water gradually warmed 

 up. On the fourth day the water was at 10°. The turbot was alive. It 

 had not eaten the mussels, and it was returned to one of the tanks from 

 which it had been taken for the experiment. I have no further data for 

 this fish. 



EXPLANATION^ OF PLATE I. . 



Fig. 1. Egg of Lot III. of Herring Spawn, 20th Feb. 1908 . . . x 19 



„ 2. „ I. ,, 22nd „ . . . . 



3. II. .... X 19 



',! 4 \\ L, II., and III. of Herring Spawn, 23rd Feb. 1908 '. x 19 



,, 5. „ I. of Herring Spawn, 25th Feb. 1908. 



)! 6. ,, II. ,, ,, ,, 



,, 7. „ I. ,, 2nd March 1908. 



>) 8. ,, II. ,, ,, ,, ,, 



„ 9. „ III. 



,, 10. ,, I. ,, 4th 



,, 11- ,, I. ,, 11th ,, 



,, 12. ,, I. „ 16th ,, 



,, 13. Hyphse of Fungus on Herring Spawn, 27th March 1908. 

 ,, 14. Fungus on Herring Spawn, ,, ,, 



,, 15. Head of Embryo of Lot I. of Herring Spawn, 25th Feb. 1908 

 ,, 16. ,, ,, ,, ,, Seen in Optical 



Section. 

 ,. 17. Empty Egg-capsule, ,, ,, 27th March 1908. 



,, 18. Egg of Lot Ic. of Herring Spawn, 21st Feb., — d. blastodisc . . x 19 

 ,, 19, 20. Eggs of Lot lie. of Herring Spawn, 24th Feb. 1908 . . . x 19 

 ,, 21. Cooled Eggs of Herring Spawn, 24th Feb. 1908, showing depres- 

 sion (de) between the blastodisc and the yolk. 

 ,, 22. Egg of Lot Ic. of Herring Spawn, 26th Feb. 1908 .... x 19 

 23. lie. .... X 19 



\\ 24. Eggs'of Lots ilc, and IIIc. of Herring Spawn, 26th Feb. 1908. 

 „ 25, 26. Eggs of Lot IIIc. of Herring Spawn, 26th Feb. 1908—6^. 

 blastopore, cr. crystal. 



