VI.— The Leaf. 



B THE MATURE LEAF. 



Historical (Venation chiefly). 



1S2S-32. De Candolle and G. Don 



1S66. Bentham . 



1. Longitudinal 



2. Oblique . 

 2a. Divergent 



3. Transverse 



1S79-84. Mueller 



1 Longitudinal 



2. Oblique 



3. Transverse 



1900 Deane . 



PAGE. 



357 



358 

 359 

 359 

 360 



36i 



362 

 362 



3 6 3 

 364 



60 



(Venation and oil chiefly). 



1899-1900 Gildemeister and Hoffmann .... 367 



1901-2. Baker and Smith 367 



1913. E. C. Andrews ... . . . . . .368 



1913 R. H. Cambage 369 



1913 R. T. Baker . 370 



1913. Baker and Smith 370 



1920 Baker and Smith . . . . . . .371 



Correlation of the leaf- venation, and chemical constituents 



of oils 37S 



The dogma of the Constancy of Species .... 381 



Differences in chemical constituents may indicate different 



species . 385 



Toxic principles affected by cultivation , . 386 



