200 THE HIGH ALPINE PLANTS 



and structure, which we have seen to be distinctive of 

 Alpine habitats. 



Several botanists in the past have paid special 

 attention to this matter. The experimental researches 

 of Prof. Bonnier of Paris on the adaptation of plants 

 to Alpine climates are of particular importance in 

 this connection. We will now glance briefly at his 

 methods and results. Prof. Bonnier studied a number 

 of species, among others the Harebell {Campanula 

 rotundifolia, Linn.), the Kidney Vetch {Anthyllis 

 vulneraria, Linn.), the Bird's-foot Trefoil [Lotus 

 corniculatus, Linn.), the Ling {Calluna vulgaris, 

 Salisb.) and the Rock Silene {Silene rupestris, Linn.). 

 Strong, well-grown examples of these plants from the 

 Lowlands were divided into two halves, as nearly 

 similar as possible. One half of each plant was 

 transported to one or other of the experimental gardens 

 on the Mont Blanc range, situated at 3,460 feet and 

 7,590 feet respectively, or in the Pyrenees to one of 

 three small gardens at 2,470 feet, 4,950 feet, and 

 7,920 feet respectively. The other half was cultivated 

 at Paris (105 feet above sea-level). The soil used in 

 each case was identical, and everything was precisely 

 similar, except the physical conditions of the chmate 

 of each experimental station, which varied with the 

 altitude above sea-level. 



The experiment was a particularly fair one, for 

 the plant grown as a " control " in the plains at Paris 

 was derived originally from the same individual as 

 the plant in one of the Alpine gardens. In such 



