272 Chronicles of Science. [April, 



above the level of the sea, while the plains of Bagneres are 1,808 feet 

 above the sea-level. It was found that the mean of the temperature of 

 the air in the shade at Bagneres was 97 o- ; on the Pic 92 0- 8. The 

 mean excess, therefore, of the temperature of the soil above that of the 

 air at the two stations, is as 10 to 17 ; that is to say, about double on 

 the mountain. The heating of the soil on high mountains is more re- 

 markable when we consider the greater cooling by radiation at night 

 as compared with the soil of the plains. 



This temperature of the soil is intimately connected with the 

 vegetation. Bamond, during fifteen years, made thirty-five ascents of 

 the Pic du Midi, and gathered seventy-one flowering plants on the 

 cone at the top of the mountain. Martins collected 131 flowering 

 plants on the highest cone of the Faulhorn, the superfice being 3£ 

 acres, and the height of the mountain 8,803 feet above the level of 

 the sea. According to Malmgren, Spitzbergen contains ninety-three 

 flowering plants. Temperature may help to explain the number and 

 variety of the species which grow on the summits of the Alps and 

 Pyrenees as compared with the flora of Spitzbergen. In the former 

 situation the roots of the plants are warmed by the soil to a much 

 greater extent than in the latter. The heat of the sun's rays in Spitz- 

 bergen is absorbed to a great extent by the dense atmosphere above 

 the soil. In Spitzbergen the ground remains frozen continually at the 

 depth of little more than a foot, and the heat of the air and sun not 

 acting powerfully on vegetation, the flora is reduced to a small num- 

 ber of plants. These live at a temperature only a few degrees above 

 the freezing point. 



It seems desirable that a similar series of experiments should be 

 made on the plants found on the tops of the mountains of Scotland, as 

 compared with those of the plains. 



Dr. W. Lander Lindsay has given an account recently of the flora 

 of Otago, New Zealand. Collections of plants were made by him in 

 the settled districts between Dunedin, the capital of the province of 

 Otago, and the Clutha river. These present a parallelogram of 

 country about sixty miles long by twenty broad. It may be cha- 

 racterized as the lowlands or district of the plains, in contradistinction 

 to the West coast region, which is that essentially of deep fiords with 

 lofty mountain walls. It consists of a succession of plains and gentle 

 uplands, with few hills of an elevation of more than 1,500 feet. Its 

 flora may be said to represent the Eastern seaboard, the Eastern 

 plains, and, generally, the settled districts of Otago. It differs ma- 

 terially from that of the Western Alps (which rise to 9,000 feet) of 

 the central great Lake basins, and of the Western fiords, whose flora 

 has, generally speaking, an alpine or sub-alpine character. Among 

 the more characteristic herbaceous plants of the district are species of 

 Olearia, Celmisia, Senecio, Cordyline, Panax, Drosera, Ligusticum, 

 Thelymitra, Gaimerotia, Gahnia, Piltosporum, Plagianthus, Aris- 

 totelia, Nestera, Baoulia, Forstera, Dracophyllum, Gentiana, Veronica, 

 Ourisia, Euphrasia, Muhlenbeckia, Pimelia, Fagus, Caladenia, Cale- 

 rophus, Carpha, Uneinia, Hymenophyllum, Trichomanes, and Lomaria. 



