138 



STRUCTURAL BOTANY 



functions. The whole capsule is covered by a well- 

 marked epidermis, which, on the apophysis, contains 

 stomata. In the upper part of the capsule the wall is 

 several cells in thickness ; the 

 hypodermal layers are colourless, 

 while those towards the interior 

 contain chlorophyll. Connected 

 with these inner cells of the wall 

 are filamentous strands, also con- 

 taining chlorophyll, which extend 

 across the intercellular space, 

 and form a junction with the 

 internal tissues. The central 

 mass is narrow below and ex- 

 panded above, assuming a barrel- 

 like shape. It is from this part 

 that the spores are produced. 

 The archesporium forms at first 

 a single cellular zone, which 

 has a hollow cylindrical form, 

 or, more accurately, is shaped 

 just like a barrel with the ends 



The archesporial layer is separ- 

 ated from the intercellular space 

 by a zone of sterile tissue called 

 the outer spore-sac. Within the 

 archesporium is the large central 

 mass of sterile colourless tissue 

 (the columella), which is con- 

 nected below by a thinner strand 

 with the tissue of the apophysis. 

 The layer between archesporium 



FIG. 63. Capsule of Funaria 

 in longitudinal section, op, 

 the apophysis ; a, a, the 



shaded) ; it surrounds the 

 columella, c. The green 

 assimilating tissue is dark- 

 ly shaded. The operculum 

 closes the top of the cap- 

 sule, above the columella ; 

 its individual cells are not 

 shown. The dark spots 

 in the epidermis of the 

 apophysis indicate the 

 stomata. Magnified 14. 

 (After Haberlandt.) 



