AMONG THE WILD FLOWERS. 179 
good lens, still better under the microscope, it 
will be seen that each sorus is covered bya 
delicate membranous zzdustum, below which 
are small roundish cases, ¢hec@, each theca 
having a short stalk, and being surrounded by 
an elastic ring, axnulus. 
_ We must suppose it to be Midsummer 
when you bring in your frond, and having de- 
tached a small portion of it containing a sorus, 
you see the black shining thece protruding 
all round from under the indusium, and as you 
watch in the drier atmosphere of the room, 
perhaps near a sunny window, you see the 
elastic rings with a sudden jerk straighten them- 
selves, at the same moment splitting open the 
thecze, and scattering the spore-dust. 
As the season advances, it is not so easy to 
find the fructification in the proper state for 
this interesting observation; the under surface 
of the fronds is then covered with the empty 
shells of the thecz, and the indusia are shriv- 
elled up. 
Most of the ferns produce their fruit thus on 
the under surface of the fronds, though varying 
much as to the disposition of it; in Scolo- 
pendrium, Hart’s-tongue, it is in lines extending 
