12 



INTRODUCTION 



Fig. 6. 



Fig. 6. — Leaf of 

 a willow {Salix ^p.). 

 b, blade; p, petiole; 

 s, stipules. 



Fig. 7. — Diagram 

 to show the essential 

 parts of a "flower- 

 ing" plant. /.r., 

 tap-root ; b .r . , 

 branch root; cot. 

 seed-leaf (cotyle- 

 don); i, internodc; 

 a.l, leaf-axil; n, node; 

 a.b, axillary bud; r, 

 receptacle of floral 

 organs; ca, calyx; 

 per, perianth; co, 

 corolla; st, stamens 

 (androecium); pi, 

 pistil (gynoecium). 



Fig. 7. 



