108 



MANUAL OP BOTANY 



of them. This springs from the air-chamber layer, but thins 

 out as it grows, forming a membranous structure which is very 

 much dissected or lobed. Besides this perichEetium, anotlier 

 membrane, the perigyniuiri; grows up from the base of each 



Fig. 867. 



Fig. 8G7. Archegoniopliore of Marchantia, bearing archegonia on under sur- 

 face. 2, 3, 4, 5, 9. 10, 11. Successive stages in development of archegonia. 

 14. Kootliair with characteristic tliiclceuing on the walls. After Kny. 



archegonium itself, surrounding it as a kind of open sac as it 

 approaches maturity. 



Both the antheridiophore and the archegoniophore are com- 

 pound, being composed of two coherent branches, the ventral sur- 

 faces of which are consequently internal. From these ventral sur- 



