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 



FIG. 137. 



3. Diagrammatic longitudinal section through the green capsule of Physcomitrium 

 pyriforme. X 14. 5. Median longitudinal section through the mature green capsule 

 of Funnria hygrometrica. X2o. 8. Profile view of mature capsule of the dorsiventral 

 capsule of Buxbaumia aphylla. g. Median longitudinal section of the same capsule ; 

 /=cylindrical air-space; at j the stomata. X 10. 10. Transverse section of the same 

 capsule, about the middle. Xg. (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 Funarta, 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. 



