EXPLANATION OF PLATE 50 



Fig. 1. Cross-section through tlie costa of Phycodrys Setchellii. 



Fig. 2. Growing apex of Hypoglossum Wodwardii. 



Fig. 3. Growing apex of Phycodrys quercifoUa. Intercalary cells and branch- 

 lets of the main axis dotted. 



Fig. 4. Growing apex of Phycodrys Setchellii. In the lower part the forma- 

 tion of cortical cells has begun. 



Fig. 5. Cross-section through the stipe of Hypoglossum Woodwardii. 



All figures drawn by the author at an enlargement of c. 700, and reduced to 

 half size. 



[436] 



