THE ALPENROSES 27 



attached to the leaf by a very short stalk. In the 

 Common Alpenrose the lower surface of the leaf is 

 thickly studded with these scales, while in the Hairy 

 Alpenrose the scales are relatively fewer, and are 

 always green in colour. 



The function of the scales is to protect the pores, 

 or stomata, which are confined to the lower surface of 

 the leaf In this way, the danger of excessive loss of 

 water by evaporation from the leaves through the 

 pores is decreased. The adaptation, though entu-ely 

 different in form, is thus fashioned to the same end 

 as that which we have just discussed in the case of 

 the Edelweiss. It is also much less marked than in 

 the latter, the different conditions under which the 

 two plants grow being suflScient to account for the 

 dissimilarities observed. Thus the Edelweiss and 

 Alpenroses furnish excellent illustrations of how 

 Nature attains her ends by different means. 



