222 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



blocked by a belt of land-ice the whole summer through, while the 

 east side, which is nearly always blocked with ice, was more open than 

 it had been for many years. These conditions, there seems little doubt, 

 depend on the prevailing direction of the winds." 



Now, the temperature of water having been lowered by the accumu- 

 lation of ice along the west coast of Spitsbergen, which is compara- 

 tively approximate to the farthest northeast influence of the Gulf 

 Stream, it seems natural to suppose that a deflection of the branch of 

 the Gulf Stream, caused by the colder arctic ice and current, the accu- 

 mulation of which former was caused by the prevailing north and east 

 winds in the arctic seas, would reach round past the south end of 

 Spitzbergen to the east coast* and would cause the unusually open sea 

 there. But the main channel of the Gulf Stream would still be towards 

 the southwest, and would afford the natural outlet for all manner of 

 ocean life which required certain temperatures, and which, such as En- 

 tomostraca, Copepoda, molluscan larvae, &c, afford food to other higher 

 organisms. 



The great quantity of such food which in ordinary summers and 

 autumns accumulates around the shores of Spitzbergen or the warm, 

 shallow summer seas off the north coast of Europe, no doubt retire to 

 deeper water ou the approach of winter. In unusually cold seasons the 

 retreat is continued, following the course of the milder Gulf Stream 

 until more temperate seas are reached. 



In the course of its retreat it is discovered by vast shoals offish, which 

 pursue these minute forms of life eveutothe uttermost limits of its pos- 

 sible extension, up certain firths and inlets of our east coast of Scotland. 

 Naturally, also, the last link of the migratory chain is taken up by the 

 enormous population of gulls and other species of sea- fowl, as we know 

 has been the case in the winter of 1884-'S5 in the Firth of Forth. 



In the log of the steam whaler Eclipse, Gapt. D. Gray (see Keport, 

 ante, p. — ), in summer repeated mention is made of the unusual abun- 

 dance of " whale food " in the Spitzbergen seas, and I am indebted also 

 to Captain Gray, through Mr. Thomas Southwell, of Norwich, for a re- 

 cord of sea temperatures of the sanie seas. 



Mr. llu^h lv. Milne, of the marine statiou atGranton, sends me some 

 temperatures taken from the Firth of Forth, extending over June, 1884, 

 to January, 188.1, taken at three points, namely, Isle of May, Queeusfen y, 

 and near Alloa. These data, in connection with the vast swarms of 

 sprats or garvies (Clupea sprattus) and the attendant thousands of 

 gulls, are useful for future comparisons, and I append them here. It 

 would be interesting to have similarly-taken temperatures of the Tay 

 estuary, which was completely deserted this season by these migratory 

 fish, and consequently by the birds also. If we had also means of 

 knowing the temperature of the Firth of Forth in 1872-'73, when a sim- 

 ilar vast migration of sprats and galls was witnessed, such data would 

 assuredly lead to most interesting, useful, and scientific results. 



