14 



MORPHOLOGY OF GYMNOSPERMS 



The roots of L. Oldhamium, long known as Kaloxylon Hookeri, 

 have been preserved so perfectly that their structure has been deter- 



FiG. II. — Lyginodendron Oldhamium: the large pith contains numerous dark 

 masses of sclerotic cells; bordering upon the pith at various places may be seen the 

 primary wood {p), comparatively scanty in amount; next is the secondary wood {s), 

 constituting almost the entire mass of the woody cylinder; a narrow zone of phloem 

 surrounds the secondary wood, and just outside the phloem, in the inner cortex (»), 

 are the leaf traces {t); next is the outer cortex (o), with numerous radially arranged 

 bands of sclerenchyma; X3. — From photograph by Kidston. 



mined with great completeness. There are usually three to eight 

 alternating xylem and phloem strands, and in the larger roots there 

 is distinct secondary growth, every stage in its development having 



