LEAF-ARRANGEMENT. 107 



Weymouth Pine, in which the leaves are much 

 longer and the stalk thicker. 



Fig. 26 represents a sprig of Box. It will be 

 observed that the increase of width in the leaves 

 corresponds closely with the greater distance be- 

 tween the points of attachment. 



FIG. 27. HCRSECHESTNUT. 



When we pass from the species hitherto consid- 

 ered to the Maples (Fig. 29), Sycamores, and Horse- 

 chestnuts (Figs. 27 and 28), we come to a totally 

 different type of arrangement. The leaves are 

 placed at right angles to the axis of the branch, 

 instead of being parallel to it, have long petioles, 

 and palmate instead of pinnate veins. In this 

 group the mode of growth is somewhat stiff ; the 

 main shoots are perpendicular, and the lateral ones 



