I04 



PLANT LIFE. 



in pairs, a pliloem (bast) laundle and a xj-leni (wood) bundle 

 being placed side by side, the xylem occupying tlie side next 



pi- 



cp — IKI^ 



Fig. iiq.— Port n fa trans ere t n F tl t f fliv m, pitli; A, secondary 



xylem forming a woody cvlmdci , /'//, phloem , i>, bundles ol meehanieal tissue (tibers) 

 among the thin-walled cells, tlie two soits naklng up the cortex; >/■. tlie epidermis. 

 Magmfied about 25 diam. — After T'rank. 



Fig. !3o. — Transverse section of a bundle pair from tlie stem of a begonia. The shaded 

 part is the xylem bundle; tlie small irregular cells abo\'e are the phloem bundle; 

 between them is a zone of generating tissue {secondaiT merlstem), the stelar cambium, 

 wliich extends also riglit and left of tlie bundle pair. 'I'lie radius of tlie section passes 

 througll Cl'\ L\ next the center. Magnified ty' dIam. — .Vfter Haberlandt. 



the center of the stem, and the phloem the side next the 

 surface (figs, in, 120J. The number and position of these 



