v] 



VENATION OF WILLOWS 



61 



The venation of the Willows has been investigated by 

 Glatfelter, who states that, in spite of variations according 



Fig. 21. Leaf of Lime, Tilia europaa, showing pinnate venation with 

 pseudo-palmate base. The secondary ribs b and c at the base come off 

 with the midrib a from a common origin : those higher up are pinnate. 

 d tertiaries forming cross-ties; e network of terminals, &c. (Ett). 



