42 



In Marchantia are also found large cells with 

 highly refractive contents, which on examination 

 proves to be mucilage. 



EEPEODUCTION. 

 Ye^etative. Multiplies by ^<?mm^, common among 

 Liverworts — gemmae arise on dorsal surface in 

 broadly cup-shaped receptacles called cupules. The 

 cups have a toothed rim, and at their bottom the 

 bright green gemmae are visible. From the bottom 

 of the cup shoot out unicellular hair-like papillae. 

 Each divides first of all by a transverse wall ; the 

 lower cell of each papilla undergoes no further 

 change, and is known as the pedicel cell. The upper 

 one divides again by a transverse wall, and then 

 longitudinally. Tangential division also takes place 

 and in this way a great mass of tissue is formed, 

 which is supported on a unicellular stalk. When 

 mature it is the shape of a bi -convex lens, with two 

 lateral indentations. At the bottom of the cup are 

 also found club-shaped papillae, the membrane of 

 which swells into a mucus and causes the ejection 

 of the gemmae whose pedicel cells are broken through. 

 The cells of the gemmae are rich in chlorophyll, and 

 the marginal ones coutain oil bodies. Certain cells 

 are also present which are large and devoid of 

 chlorophyll. When the gemmae have been pushed 

 out of the cup, and lie exposed to light on damp 

 ground, the two lateral depressions, which are the 

 growing points, form the first flat shoots of the 



