286 



BOTANICAL GAZETTE 



divide, giving rise to a semicircle of bundles with xylem on the 

 concave side, facing the xylem of the bract bundle. The semicircle 



Figs. 3-21. — Pimts maritima: figs. 3-9, course of bundles to bract and scale in 

 upper half of strobilus; fig. 3, origin of bract bundle (/>) and scale bundles (4 remaining) 

 in strobilus cylinder; fig. 4, two upper bundles uniting; figs. 5-9, transverse sections 

 of sporophyll, bract bundle remaining undivided, scale bundles giving rise to several 

 bundles; figs. 10-12 and figs. 13-15. from lower half of strobilus, scale bundles decreas- 

 ing in number and originating nearer to bract bundle as base of cone is approached: 

 figs. 16-20, from lowest sporophylls, bract and scale bundles (bs) one in origin; fig. 

 21, transverse section of one of lowest sporophylls; X16. 



Figs. 22-29. — Pinus Banksiana: figs. 22-24, f rom middle of cone, bundles closing 

 up to form concentric cylinder; figs. 25-29, from lower portion of cone, phloem creeps 

 about xylem so that concentric bundle is formed; X34- 



fn all cases four bundles result (figs. 5, 12, 15, 20, 24, 29), the lower supplying 

 the bract, the remaining three the scale. 



