202 THE HIGH ALPINE PLANTS 



one of the Alpine gardens. The latter is a dwarf 

 plant. The stem is shorter, and the lower leaves 

 closer together. The flowering shoot is much shorter 

 and more hairy. It bears only a single flower, 

 which is, however, larger than any one of the flowers 

 borne in the branched raceme of the Lowland plant. 

 The coloration of the Alpine specimen is also a 

 very much deeper blue. 



The following are, in general, the conclusions to 

 which Prof. Bonnier was led, though in some cases 

 comparatively little modification was observed. The 

 whole habit of the species cultivated in the mountains 

 was much shorter and more dwarf than in the plains. 

 Sometimes they only reached one-tenth of the height 

 of the Lowland examples. The stem was shorter, and 

 much buried in the earth. The underground portions 

 of the stem and roots were better developed, the 

 above-ground stems and shoots were more hairy and 

 spreading, and tended to cling closer to the soil. 

 The internal structure of both stem and leaf was 

 profoundly modified. The leaves were, in general, 

 nearer together, more hairy, relatively thicker and 

 smaller, and of a much deeper green colour, more 

 chlorophyll (see p. 10) being developed. The flowers 

 were relatively larger and more strongly coloured. 



The three principal factors of the Alpine climate 

 which call forth these changes are the more intense 

 illumination, the drier atmosphere, and the lower 

 average temperature. The first has a particularly 

 powerful influence. 



