226 THE ALPINE FLORA 



snow. For in winter the plant is Jiving and making ready for 

 the rapid normal development. It is feeding roots, swel- 

 ling buds, and setting all in order for the great evolu- 

 tion. The sun appears; every root and an alpine's roots 

 are countless is quickened to activity, to toil in the first 

 instance for bud and flower alone, then for the leaves. 

 With the earliest species the flowers outrun the foliage 

 or respiratory organs, whose growth is postponed as last 

 year's leaves are sufficient for immediate needs. The long 

 winter torpor over, a time we have seen of but comparative 

 rest, all this concentrated energy is prodigally outpoured. 

 With days of continual light, clear and intense, fourteen 

 or even sixteen hours long with a sun of power unknown 

 below with abundant water of stream or vapour light, 

 heat and moisture, all in amplest measure with myriads 

 of unwearied roots and radicels there is no lack of activ- 

 ity here. Now let us look at the fetter, that is to say 

 the causes that dwarf the plant and tie it flat and close to 

 the ground. 



First there is the familiar fact that night is the time 

 for growth and expansion of tissue. By day growth is 

 inversely proportionate to exposure to the sun. It clearly 

 follows, therefore, that, the alpine nights being frost- 

 bound, nocturnal growth is impossible and that only in 

 the brief summer twilight, when the sun-rays have lost 

 their power, can any development be made. Hence the 

 internodes are extremely short and the general character 

 of the stems and branches is much stunted. Just as by day 

 the excessive heat and strength of the sun stimulates the 

 enlargement and vivid coloration of the petals, so it forbids 

 a rapid extension of stalk and leaf. No time of growth is 

 granted to these organs except the space between twilight 

 and the chilling of the air. It is true that the loss is made 

 up during the latter part of autumn, when the plant takes 

 advantage of a moment of grace to repair her respiratory 



