286 



SPOROPHYTE OF MARCHANTIA 



(Figs. 191, 195, A). The antheridia retain their original position 

 upon the branch, where they appear in cavities, as shown in 

 Fig. 192. 



The most important and significant departure in Marchantia is 

 seen in the germination of the gametospore which divides into an 

 inner and outer cell as in Ricciocarpus (Fig. 193, B). The inner 



FIG. 193. Germination of the gametospore: A, section of a mature ar- 

 chegonium with canal cells dissolved, thus forming a passageway to the 

 large female gamete, g. B, sectional view of base of archegonium, show- 

 ing the germinating gametospore in two-cell stage. The perianth, p, is 

 seen growing up about the archegonium. C, later stage in growth of the 

 gametospore. The lower cell shown in B is forming stalk cells, while the 

 outer cell has produced densely granular cells that will later by further di- 

 vision form spore mother cells and elaters. 



cell, however, by a series of divisions, forms a rudimentary stalk 

 and the lower part of it, known as the foot, comes into close 

 contact with the tissues of the plant from which it absorbs nour- 

 ishment (Figs. 193, 194). The outer cell divides, forming a 

 spherical mass of cells that resembles the capsule of Ricciocarpus. 

 Some of these cells of the capsule develop as spore mother cells, 



