flowers of the same kind increases with the ahitude, and 

 that in some cases there is a corresponding increase in the 

 intensity of the scent of the flower. 



While many of the characteristics of Alpine flowers 

 are to be explained as a direct result of the conditions of 

 life at high altitudes, it is probable that the process of 

 natural selection has also had a good deal to do with their 

 production. One of the principal objects of the life of a 

 flowering plant is to produce seeds. It has been shown that, 

 generally speaking, more numerous and healthier seeds are 

 produced when the seed-producing apparatus of a flower is 

 fertilised by pollen from the stamens of a flower of a 

 diiferent plant. Hence arrangements have to be made 

 by plants for the conveyance of their pollen from flower to 

 flower. This is sometimes effected by the wind, but much 

 pollen is lost, so that this is manifestly a very wasteful 

 method. Plants have therefore adopted the more economical 

 plan of getting insect visitors to do this carrying business for 

 them. The bright colours and sweet scents are to attract 

 insects to the flower, and honey is provided for their 

 entertainment there. It is generally believed that the total 

 number of insect visitors in the Alps is less than in the 

 plains, and therefore the competition for their services being 

 more severe, greater attractions in the form of brighter 

 coloured flowers and more abundant honey have to be 

 provided for them. But, unfortunately, the direct observa- 

 tions of H. Miiller do not confirm this view. There can be 



XX 



