CONTACT- PRESSURES. 



255 



in large heads of Oynara Scolymus (fig. 536). Here the primary 

 members are entirely wanting, but their axillary shoots neverthe- 

 less present perfect curve-systems of constant (55 -|- 89) and falling 



Fig. a.—Pinus Pinea. Transverse section of the apex of the young seedling, 

 6 inches high : system (5 + 8). 



systems (fig. 536). That the growth-centres of the primary 

 subtending leaves are actually existent, though they may 

 not be visible, appears undoubted : their rate of growth has not 

 become sufficiently great to raise them above the surface of 



