Growth Integration 



99 



Illustrations from Plants 



But it is in tlie plant world that those graded scries of 

 homonynious parts in individual organisms are most strik- 

 ingly seen. It occurs in what is perha])s its most typical, 

 least modified expression in the arrangement and size rela- 

 tion of parts in the leaves of many ferns and palms. Hut 

 the compound leaves of innumerable flowering ])lants illus- 

 trate it very beautifully. Figures 58, 59, and 60 {.icacia, 

 Vicia and Cassia) show three types of compound leaves 

 based on the mode of gradation of the leaflets. These might 



FIOURE 58. ACACIA ELATA. 



