The Origin of Land Plants 



93 



siderable length, and facilitates the disposal of the 

 spores developed in the upper region of the sporo- 

 phyte (Fig. 8, B). The latter forms a capsule en- 



FlG. 10 



Diagrams illustrating the evolution of the sporophyte in the 

 liverworts. The shaded areas show the extent of the sporog- 

 enous tissue ; f, the foot. 



A Riccia. 



B Porella. 



C Anthoceros. 



closing the spores, together with peculiar sterile 

 cells, or elaters, formed from a portion of the po- 

 tentially sporogenous tissue. 



