226 Plants and their Ways in South Africa 



moist kloofs and other damp, shady spots. One of the most 

 familiar liverworts is Marchantia. It has a flat, leaf-like, 

 forked thallus growing close to the soil. On the under side 

 are thread-like rhizoids, which serve the purpose of roots. 

 On the thallus are little cups, containing small green bodies. 

 They are buds which grow from the bottom of the cups. They 

 become loosened, and are washed out to other places, where 

 they form new plants. Umbrella-like bodies are often to be 

 found growing up from the thallus. These stalks are of two 

 kinds. At the top of some are 



TT 



stars of nine or more rays. 

 Others have round, scalloped 

 tops. Sunken in them are club- 

 shaped bodies called antheridia 

 {anther- like). They contain many 

 small nucleated cells (sperm -cells), 



Fig. igq.— -Marchantia polymorpha. I. Thallus with five anther-bearing 

 umbrellas. II. Thallus with an umbrella bearing the egg pockets beneath. 

 (From Thom6 and Bennett's " Structural and Physiological Botany".) 



which escape when the antheridia are ripe, and swim about by 

 means of tiny lashes, cilia, attached to them. They are ex- 

 tremely small, and can only be seen by means of a microscope. 

 Underneath the stars on the other stalks, protected by delicately 

 fringed curtains, are bottle-shaped bodies, each containing an 

 egg-cell. These are sought out by the sperm-cells, which unite 

 with them just as the nucleus in pollen grains unites with the 

 egg-cell in an ovule of higher plants. As a result of this union. 



