32 



T O R R E Y A 



3 



V 



ll 





i'WoV 



psf 



y? .." "_t»!^«W ■'•'' 



4 



Fig. 3. Photograph through a lower region of the meristem showing parts of several 

 diaphragms, two leaf bases and the beginnings of provascular tissue in stem and leaf. 



Fig. 4. Three stages in the development of a row of aerenchymatous tissue. Most of 

 the division walls are opposite those in vertically adjacent cells. 



