134 
MANUAL OF NATURE STUDY. 
a young frond just coming out of the ground, watch 
it until it is fully matured and describe its peculiar 
action. 
These ferns do not produce flowers as all the 
other plants you have studied, consequently they 
have no seed factory; but they have another way 
of reproducing themselves, which is very interest¬ 
ing as well as mysterious. Look on the under side 
of your fern frond. All ferns are not alike in this 
respect, but in all probability if you look closely you 
will find generally along the mid-rib and larger side- 
veins what at first appears to be a kind of papillae. 
These papillae, or usually conspicuous bodies on 
the under side of the pinnae, are called the sort 
(singular, sorus) or fruit-dots. Observing their posi¬ 
tion, notice the thin scale-like covering, indusium . 
But if you remove the indusium you will find attached 
generally by very delicate stalks, an oval or spherical 
body. These free ends are spore cases which con¬ 
tain a powdery mass known as spores. This mass 
of spores is very similar in appearance to the 
powdery cloud that escapes from a ripened “puff 
ball.” To the naked eye, these spores have no 
form, but by the aid of the microscope, it is clear 
that they are just as definite in form as this round 
earth upon which we live. Strange to say, too, 
each little spore contains the possibilities of a new 
plant, just as seeds do in the flowering plant, but 
