164 



GENERAL BOTANY 



stiff and flat only 

 after a few days. 

 This is very 

 obvious in the 

 Mango, and in 

 BROWNEA COC- 

 CINEA, and is 

 really a very 

 common occur- 

 rence. 



The red or 

 purple colour 

 appears in some 

 mysterious way 

 to protect the 

 delicate tissues 

 of the young 

 leaves from the 

 injurious effect of 

 intense light and 

 heat, probably by 

 absorbing the 

 rays which com- 

 pose the yellow- 

 green part of the 

 spectrum, and we 

 do not find this colouring nearly so common, in plants 

 of the temperate climates where the sun is less powerful. 

 The vertical position of the hanging blade (figs. 6, 

 11 and 42) also protects the leaf from the rays of the 

 sun, for during the middle part of the day where the 

 sun is vertically over head and his rays are most 



FIG. 42 

 FLEMINGIA GRAHAMIANA, W. & A. 



