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 
Fic. 137. 
3. Diagrammatic longitudinal section through the green capsule of Physcomitrinin 
pyriforme. X14. 5. Median longitudinal section through the mature green capsule 
of Funaria hygrometrica. X20. 8. Profile view of mature capsule of the dorsiventral 
capsule of Buxbaumia aphylla. 9. Median longitudinal section of the same capsule ; 
Z=cylindrical air-space; at s the stomata. X10. 10. Transverse section of the same 
capsule, about the middle. %g. (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 /unaria, its structure shows a_ peripheral 
sclerotic band, which merges gradually into thinner-walled parenchymatous 
tissue: centrally les a strand of thin-walled water-conducting tissue, 
without cell-contents when mature, surrounded by a thicker-walled sheath. 
