104 ABOUT A FERN. [CHAP. 
from it. Along the rhizome of the Bracken-fern, on 
each side, there runs a line, paler in colour than the 
rest of the stem, and it is from these lines the fronds 
take their origin. In the Common Polypody (fig. 97), 
Bi 
Ce> 4) fb 
; ih F Y) 
By itZa Yy 
Fic. 97- 
which also has a creeping rhizome, the fronds are pro- 
duced indifferently from the sides or the upper surface. 
This species, instead of creeping underground, like 
the Bracken, traverses the surface, and to afford it 
