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276 



NATURE 



[January 21, 1892 



surface, Salix polaris being the most common form. Of 

 other species found, the following have, up to the present, 

 been recognized : Salix herbacea, Dryas octopetala, Betula 

 nana, Polygonum viviparum, Saxifraga ccespitosa or an 

 allied species, mosses, &c. 



From Kunda we went to Hellenorm in Livonia (8), 

 where we were welcomed by the old Siberian traveller, 

 A. Th. van Middendorff, who took a great interest in my 

 researches. On the day of our arrival Prof. Schmidt 

 found a leaf of Salix reticulata in a bed of clay at Samhof. 

 In another clay-bed in the vicinity, at Kinzli, I found 

 Dryas octopetala, Betula nana, Salix sp., mosses, &c. 



Then we went to Fellin (9), where I found the Arctic 

 plants at two different localities, Pingo and Wieratz. 

 The species obtained were Dryas octopetala, Betula nana, 

 Salix reticulata, Potamogeton sp., &c. I then parted 

 from Prof. Schmidt, and went to Rjeshiza (10), in the 

 Government of Vitebsk, accompanied by Dr. J. Klinge, of 

 Dorpat. In Rjeshiza we were welcomed by Dr. E. 

 Lehmann, a skilful botanist ; and on the very day of our 

 arrival we discovered the following Arctic plant-fossils, 

 Dryas octopetala, Betula nana. Polygonum viviparu?n, 

 &c., in two different localities in the vicinity of the town. 

 My ignorance of the Russian language made it impossible 

 for me to continue my researches further eastwards into 

 the interior of the country, and I consequently turned 

 westwards to Konigsberg, in Eastern Prussia. There Prof. 

 A. Jentzsch reminded me of the discovery of Hypnutn 

 turgescens, in an alluvial deposit at Kuhrische Nehrung, 

 made by Berendt many years ago. As this is a mountain 

 species, it is possible that it may have been found in a 

 glacial fresh-water deposit, and this locality has con- 

 sequently been indicated on the sketch map (11). 



Accompanied by Prof. A. Jentzsch, of Konigsberg, and 

 by Prof. H. Conwentz, of Danzig, I now went to 

 Marienburg, in Western Prussia, and at Schroop (12), 

 about 10 kilometres south-east of this town, a locality 

 yielding Arctic plant-fossils was discovered. They occur 

 here under precisely the same conditions as in Scania 

 or at Kunda, in Esthland ; Salix polaris and Dryas octo- 

 petala being found in the lower strata, whilst Betula 

 nana occurs somewhat higher. The next locality 

 discovered was at Krampkewitz (13), near Lauenburg, 

 in Pomerania, whither I had gone with Prof. Conwentz. 

 The plant-fossils found were Dryas octopetala, Betula 

 nana, and some others. 



Owing to heavy rains, a visit to Breslau proved fruit- 

 less, and for the same reason the fresh-water deposits 

 near Waren and Rostock were inaccessible, but acting 

 on the advice of Prof. E. Geinitz, of Rostock, I examined 

 a small peat-moss at Nantrow (15), north-east of Wismar, 

 where I found Betula nana and some Salices in mud and 

 sand underneath the peat. The following day I examined 

 the sections at the great North Sea-Baltic Canal at 

 Holtenau, north of Kiel (16), under the guidance of Prof. 

 R. V. Fisher-Benzon, of Kiel. We succeeded in finding 

 two fresh-water basins yielding plant-fossils. The first 

 basin, of which only a sm^ll portion now remained, con- 

 tained fruits of Betula nana, together with some other 

 species, not yet determined, but probably indicating a 

 sub-Arctic climate. In the other basin, which was also 

 cut through by the canal, the glacial fresh-water strata 

 underneath the peat were laid bare, yielding abundant 

 leaves of Salix polaris, sometimes intermingled with 

 those of Dryas octopetala, mosses, &c. 



In view of these facts, thus briefly communicated, I 

 think it may be accepted as proved that the Arctic flora 

 flourished on the plains south and east of the Baltic 

 round the margin of the ice-sheet, and some time after 

 the inland ice had melted away (see the accompanying 

 sketch map). There can also be hardly any doubt that 

 this same flora may have lived round the margin of the 

 great northern inland ice at the climax of the glaciation. 

 For otherwise it is difficult to understand how it could 



NO. 1 1 60, VOL. 45] 



have obtained so great an extension as from Suffolk to 

 Kunda, in Esthonia, or why it should have flourished 

 during so long a time after the amelioration of the climate, 

 which caused the melting of the ice, had commenced. 

 The fresh-water deposits with Arctic plants are sometimes 

 so thick that they probably indicate an interval of several 

 thousand years, during which the Arctic flora prevailed. 

 If the margin of the ice-sheet at the climax of glaciation 

 had been surrounded by a forest growth, this ought still 

 more to have existed round the margin of the retreating 

 ice. But as we have shown that this is not the case, we 

 are entitled to conclude that the Arctic flora formerly 

 flourished, not only round the margin of the great 

 northern inland ice, but probably also over a part at 

 least of the area between this ice and the glaciers of the 

 Alps. In connection with this, it ought not to be over- 

 looked that the Arctic tundra-fauna, which Prof. Nehring 

 discovered at Thiede, underneath the steppe-fauna, per- 

 fectly harmonizes with this view, as this locality is 

 situated relatively near to the outermost margin of the 

 great northern ice- sheet. The existence of Salix polaris 

 in Suffolk and Norfolk may also be considered as a 

 strong argument for the same hypothesis. Thus the 

 theory advanced by E. Forbes so far back as 1846 — that 

 the Alpine flora of Europe, so far as it is identical with 

 the flora of the Arctic and sub-Arctic zones of the Old 

 World, is a fragment of a flora which was diffused from 

 the north, and that the termination of the glacial epoch 

 in Europe was marked by a recession of an Arctic fauna 

 and flora northwards— may now be regarded as defini- 

 tively proved. 



A. G. Nathorst. 



CYCLONES IN THE ARABIAN SEA> 



THIS discussion was undertaken primarily by the 

 Meteorological Office with the object of throwing 

 some light on the very exceptional storm which was ex- 

 perienced at Aden in the summer of 1885, but advantage 

 was taken of this opportunity to produce synchronous 

 weather charts of the Arabian Sea for a hmited period, 

 since it was felt that such charts would be of especial 

 interest, dealing as they do with a part of the ocean 

 which is subject to the regular change of monsoon winds. 

 The charts also exhibit the occurrence of a second cyclone 

 which had originated over the eastern portion of the 

 Arabian Sea before the full effect of the first disturbance 

 had passed away. The Gulf of Aden and the northern 

 portion of the North Indian Ocean are rarely visited by 

 cyclones or typhoons, and consequently the occurrence 

 in these waters, in the summer of 1885, of a violent 

 cyclone, causing the loss of several vessels, among them 

 the German corvette Augusta, and the French despatch- 

 boat Renard, attracted considerable attention. The 

 number of ships' logs which have been collected and 

 utilized in the preparation of the charts is 239, and the 

 information has been obtained from all available 

 sources, including our own Navy and mercantile marine, 

 and those of many foreign countries. For the first 

 few days of the period discussed, the normal conditions 

 were apparently prevailing over the Arabian Sea, the 

 wind was north-westerly near the Indian Peninsula, 

 but the south-west monsoon was blowing steadily near 

 the African coast and for some distance over the sea on 

 the western side of the district. Until about May 20, 

 the weather in the neighbourhood of Ceylon seems to 

 have been quiet, and the wind fairly steady from the 

 south-westward. On the 20th, Her Majesty's ships 

 Briton and Woodlark experienced somewhat disturbed 

 weather at Trincomalee, the squalls attained the force 



' " Daily Weather Charts for the Period ot Six Weeks ending June 25, 

 1885, to illustrate the Tracks of Two Cyclones in the Arabian Sea." 

 (London : Published by the authority of the Meteorological Council, iSgi.) 



