280 



BRYOPHYTA 



Meanwhile, however, other changes supervene, and they are especially 

 marked in the amphithecium ; but all such changes are nothing more than 

 secondary modifications of the amphithecial tissue : there is no develop- 

 ment of new parts, however greatly the external appearance of the sporo- 

 gonium may be affected by their presence. They may be considered in 



J. 





FIG. 737. 



3. Diagrammatic longitudinal section through the green capsule of Physco>iiitriitiii 

 pyri/oruit-. X 14. 5. Median longitudinal .section through the mature green capsuli- 

 of J'unaria hygromctrica. X 20. 8. Profile view of mature capsule of the dorsiventral 

 capsule of Kii.i'/'iititiiiu afliyllii. 9. Median longitudinal section of the same capsule ; 

 /=cylindrical air-space; at A th. -.i..mata. Xio. 10. Transverse section of the saint- 

 capsule, about the middle. '/.<). (After Haberlandt.) 



succession from below upwards. The lower part of the sporogonium which 

 forms the seta elongates more or less in different types : where well 

 developed, as for instance in Funaria, its structure shows a peripheral 

 sclerotic band, which merges gradually into thinner-walled parenchymatous 

 tissue : centrally lies a strand of thin-walled water-conducting tissue, 

 without cell-contents when mature, surrounded by a thicker-walled sheath. 



