256 REPRODUCTION OF MARCHANTIA 



enchyma of the leaf and it is manifestly protective and adapted 

 to photosynthesis. The structure of the lower cells of the thallus 



FIG. 188. Section through the center of the thallus of Marchantia, show- 

 ing one of the air chambers and chimney-like air pores in the epidermis 

 ch, palisade-like chlorenchyma arising from bottom of air chamber. The 

 lower cells of the thallus are nearly colorless and filled with watery solu- 

 tions or mucilage, r, rhizoids ; /, leaf-like plates of cells. 



and the distribution of the rhizoids and ventral plates are essen- 

 tially as in Ricciocarpus. 



FIG. 189. Diagram of a section of one of the cups shown in Fig. 186 

 g, buds or gemmae associated with small- glandular cells. 



Marchantia, as in many of the liverworts and some mosses, 

 multiplies extensively by means of buds or gemmae. They are 

 borne in cup-shaped receptacles and consist of small lense-shaped 

 masses of cells which are freed from the thallus by the swelling 



