150 



PHILOSOPHICAL NOTES ON 



Erect peltate leaf of 

 Diphylleia cymosa. 



Fig. 37. 



Horizontal palmately lobed 

 leaf of the same. 



centre, so that this leaf is not unlike a branch of Woodruf 

 (Sherardiaj with v&rticillate leaflets. 



12. A pinnate leaf, if it were erect, would be a branch with 

 either opposite or alternate leaves. 



13. Amorphophallus Bivieri, Titanum, and others have only one 

 decompound erect leaf, and its divisions are placed regularly all 

 round the main petiole. This leaf is the whole tree. 



14. The leaves of Tlialictruui aquilegifolium and ]JU7yuratum are 

 among the most interesting examples of leaf-branches. At the 

 point of emergence of each sub-division there are three bract-like 

 scales alternating with the sub-divisions. As the division of the leaf 

 is trichotomous, these scales are evidently abortive divisions, for 

 which there would be no room in this horizontal leaf-branch. Make 

 it erect, that is stem-like, and its nature is at once revealed. The 

 pinnse become branchlets, and the alternate scales become abortive 

 branchlets, so that the system was originally a branch with 



a 



Fig. 38. 



