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General Botany 



branches which we commonly call the moss plant. Because of the 

 numerous buds developed on the protonema, the moss plants 

 stand in thick clusters or masses. 



Fig. 2go. A moss plant {Mnium). £ is a vegetative branch, B a branch that 

 produces eggs, and A a branch that produces sperms. After fertilization, an 

 upright stalk bearing a spore case (C) develops from the egg. ^' is a longitudinal 

 section of a female branch, showing three egg cells in the archegonia in which 

 they are produced : B' is a section of a male branch, showing three of the 

 antheridia that produce the sperms. 



The upright leafy stems of the moss also have the power of 

 producing protonema-like branches which spread still farther over 

 the soil, thus serving to multiply the plants and to make the plant 

 mass denser and larger. In some mosses with horizontal or in- 

 clined stems, the stem tips when in contact with the soil develop 

 rhizoids and give rise to new branches, much as the stems of the 

 raspberry develop new plants. These methods of vegetative 

 propagation are common among the mosses, and some mosses 

 are not known to multiply in any other way. Some mosses 

 also produce gemmae. 



Gametophyte and sexual reproduction. Archegonia and an- 

 theridia are produced on the mature upright stems of most 

 mosses. The antheridia are many-celled structures, each of 

 the smaller interior cells of which produces a sperm. The 



