356 



BOTANICAL GAZETTE 



[NOVEMBER 



Figs. 9-12. — Fig. 9, median longitudinal section of mature strobilus just before 

 pollen shedding, showing "elongating region" of axis and 4 sporophylls; xylem of 

 bundle black; note that xylem becomes centrally placed in upper portions and does 

 not extend as far into stalks as phloem; numbers at left (13-22) indicate approximately 

 levels of cross-sections of strobilus shown in figs. 13-22; fig. 10, median section of open 

 sporophyll, showing elongated stalk, open sporangia, and solitary stoma in center of 

 depression of disk; fig. 11, tangential section of mature epidermis, showing mechanical 

 thickenings on walls; fig. 12, cFOSs-section of mature epidermis, with microspore, at 

 time of shedding; figs. 9, 10, X36; iigs. 11, 12, X475. 



