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A TEXT-BOOK OF BOTANY 





moss plant, which does not produce spores, but which does 

 produce sex-organs, is the gametophyte generation in the 

 life-history. It is plain that the ciliated sperms are organ- 

 ized for swimming, and that fertili- 

 zation can take place only when there |k ^* 

 is sufficient moisture for this purpose. 



Fio. 172. Developing sporophyte of a moss: A , young 

 sporophyte developed from egg in archegoniutn; 

 B and C, more advanced stages, in which the 

 sporophyte is elongating and becoming anchored 

 in the leafy plant. After GOEBEL. 



FIG. 173. A common moss- 

 bearing mature sporo- 

 phytes, which are long- 

 stalked spore -cases. 

 After SCHENCK. 



