296 



r 



MacMillax: Ocservatioxs ox Nereocvstj 



s 



Fio. 19. Cross section of mucilage duct in the lamina. Section made immedi- 

 ately above pneuinatocvst. Plant 12 cm. long. X 335- Should be compared with 

 Fig. If and indicates a possible relation between the structures classed as cryptostomata 

 and the mucilage ducts. 



F 



Fic. 20. Cross section of old mucilage duct in stipe. Plant 12 cm. long. Secre- 

 tion-cells not shown. X335- 



Fig, 21. Cross section of pneumatocyst wall. Mucilage duct in center. X 335- 

 Fig. 22. Origin of paraphyses in sorus. Mature plant. X 335- 

 Fig. 23. Origin of sporangia in sorus. Mature plant. X S^I. 

 Fig. 24. Cross section through mature sorus showing paraphyses and sporangia. 

 In the latter spores are indicated. X 335- 



i 



