64 THE VEGETATIVE FUNCTIONS OF PLANTS 



L_Jn 



Fig. 48. 



Fig. 49- 



Fig. 48. — White lupine {Lupiniis albiis). Made 

 semi-transparent by being placed for several hours 

 in a weak aqueous solution of potassium hydroxide. 

 After this treatment the fibro-vascular system may 

 be clearly seen (through the surrounding tissues) 

 by transmitted light, cot, cotyledons; /;, hypocotyl; 

 r, main root; br, hr^, branch roots of different ages. 

 Note the endogenous origin of the branch roots. 



Fig. 49. — The system of leaf-veins in a leaf of the 

 common rubber-plant {Ficiis elaslka). The veins are 

 connected with the root by means of the vascular 

 bundles extending through the stem and roots. 



