38 



MORPHOLOGICAL DEVELOPMENT. 



gradations between the simple, very small leaf, and the large 

 composite leaf, containing sometimes even seven leaflets. 

 Figs. 50 to 6-i, represent leading stages of the transition. 



30 





58 



(&r x 



e^A 



J9 



What determines this transition? Observation shows that 

 the quintuple leaves occur where the materials for growth 

 are supplied in greatest abundance; that the leaves become 



