FERNS 187 
derive no nourishment from them (§ 41). This habit be- 
longs chiefly to the moist tropics, where plants may obtain 
sufficient moisture from the air without sending roots into 
the soil. 
108. Sporophytes.—If an ordinary fern be examined, it 
will be discovered that it has a horizontal underground 
stem or rootstock (§ 27), which 
sends out roots into the soil, and Me is 
one or more large leaves into \ 
the air (Fig. 179). These leaves, 
appearing to come directly from 
the soil, were once supposed to 
be different from ordinary leaves 
and were called fronds ; but al- 
though the name is still used in 
connection with fern leaves, it 
is neither nec- 
essary nor ac- 
curate. These 
leaves are usu- 
ally compound, © 
branching eith- 
ck pinnately OL Fic. 179.—The habit of an ordinary fern (sporophyte), 
palmately. showing the horizontal rootstock sending out roots and 
leaves, and also the peculiar rolled tip of the developing 
There are leaves. 
two peculiari- 
ties about fern leaves that should be noted. One is that 
in expanding the leaves seem to unroll from the base, as 
though they had been rolled from the apex downward, the 
apex being in the center of the roll. When unrolling, this 
gives the leaves a crozier-like tip (Fig. 179). The other 
peculiarity is that the veins fork repeatedly (Fig. 180). 
This combination of unrolling leaves and forking veins is 
very characteristic of ferns. 
Probably the most important fact about the fern body 
