1 1 6 Plants and their Ways in South Africa 



dew and open out as water runs down their inner surfaces. 

 As this water is absorbed the stipules close over the leaves 

 again. 1 



It would take a much longer chapter than this to tell of all 

 the curious devices by which plants are protected against in- 

 SOlation or exposure to the direct rays of the sun. One of 



FIG. 103. Leave 



n sleep position. 



the most remarkable methods is shown by a group of plants 

 described by Dr. Marloth as possessing " window leaves " 

 (Fenster- Blatter}. These plants have the green portion of 

 their leaves underground, only the colourless tips being 

 exposed ; here the light enters and is diffused to the chloro- 

 phyll below. Beneath these " windows " in some plants, for 

 example Mesembrianthemum rhopalophyllum, S. and D., are found 



1 This plant supplies a ferment which the natives in some curious 

 way have learned to use in raising bread. 



