ON BUDS 13 



those of the Wallflower ? Because, as I have already 

 mentioned, the seeds of the Wallflower are thinner than 

 those of the Mustard, so that there would not be room 

 for the four folds of the doubled leaves. 1 



In illustration of the influence which the form of 

 the bud exercises on the shape of the leaf I may refer 

 to my paper in the ' Contemporary Review ' for May, 

 1885, to several memoirs in the ' Journal of the Linnean 

 Society,' and to my book on ' Fruits, Flowers, and 



Fig. 16. Sections of Seed of Wallflower. Transverse 



(left) x 10, and longitudinal (right) x 22. 



/;. radicle : (', cotyledon. 



Leaves.' I will here only mention one or two cases. 



The leaves of the Tulip Tree (Liriodendron tulipifera) 



have long attracted attention from the peculiarity of 



their form. They are saddle-shaped, abruptly truncate 



at the end ; or, in the words of Bentham and Hooker, 



1 sinuato-4-loba.' I long wondered what could be the 



purpose or the advantage to the tree of this remarkable 



1 This interesting subject is dealt with more fully in my book on 

 Seedlings. 



