58 



LIVERWORTS 



(a) Antheridia in Marchantia are borne by special upright 

 branches which develop from the ends of horizontal branches 



FIG. 25. Marchantia polymorpha. Male gametophyte. The last figure 

 shows numerous antheridia sunken in the upper surface. 



of the thallus. The special branch is umbrella-shaped and 

 in its upper surface grow many antheridia. An antheridium 



FIG. 26. Marchantia thallus with two gemmae cups. 



is a rounded or oval body attached to a slender stalk. The 

 whole structure is imbedded in the upper surface of the thallus. 



