SOME CHARACTERISTICS OF ALPINES. 53 



appeal to us more powerfully, and to these let us now 

 pass on. Their richness of colour, the marked con- 

 trasts of colour, and their sensitiveness to the sunshine, 

 are features which are specially striking. Some of the 

 flowers appear to follow the sun in shining forth and 

 disappearing according as the sky is clear, or clouds 

 keep back his rays. Is it light or heat which regulates 

 their movements ? Is their unfolding due to the 

 increased light that comes when the sun breaks through 

 the clouds, or to the additional warmth ? Once more 

 we may find in the pages of Kerner some explanation 

 of the subject, for, after giving particulars of experi- 

 ments, he sums them up as follows : " As we know, if 

 rays of light strike any object and are not entirely 

 reflected from its surface, they warm it. This probably 

 is the case with the Gentians, and the phenomenon 

 may be explained as follows. The light vibrations are 

 communicated to the flowers and converted into 

 vibrations of heat. This heat produces changes in 

 the turgidity of the tissues, affecting their tension and 

 growth. The active energy of the heat is converted 

 into another form of movement, which ultimately 

 alters the position of the petals, and we see the flowers 

 opening.*' This explanation arouses an interesting 

 speculation as to the way in which certain pigments 

 possess the power of converting heat into light. It 

 appears probable that such a power is possessed, and 

 that the dark fluffy coats of the Alpine Anemone, and 

 the Alpine Ranunculus (Ranunculus glacialis) are of use 

 in assisting the opening of their corollas. 



Colour contrasts, as has been said, are very marked 



