128 A TEXT-BOOK OF BOTANY 



a life-history may be indicated as follows, a formula in 

 which the fruit-like body is designated by F: 



P\ - Spera >-spore-P j - Sperm >-spore-P,etc. 

 I egg / I -egg / 



The formula shows an alternation of the ordinary plant 

 body and the fruit-like body; the latter always resulting 

 from the act of fertilization, and the former coming from 

 an asexual spore. This alternation becomes a conspicuous 

 feature of higher plants. 



