125 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: 
{ —sper ai { —sperm\ 
P or, po ene : =eps pf —spore—P, etc. 
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. 
