A Study of Leaves 



55 



matches for stamens, etc., the same apparatus can be uSed for 

 making solid diagrams of flowers." 



Have you noticed by what other ways leaves manage to get 



Fig. 65. — Diagram of forms and margins of leaves. 



light ? Some have much larger leaves below, so that the upper 

 ones cover only a portion. It is more economical for the 

 plant to extend the lower leaves on long petioles. The upper 

 leaves let the light to the lower ones in some cases by being 

 much cut or lobed. In this way the differences in the upper 

 and lower leaves of Bnpleurum difforme^ L., and Scabiosa come 



