The Sporing of the Fern 265 
fulfil all the offices of foliage, while others, which 
are curiously contracted, produce sporangia and do 
nothing else. The spore-bearing fronds of the sen- 
sitive-fern, browned and desiccated by the winter - 
storms, are conspicuous amid the tender greenery 
of low-lying fields in early spring. The royal 
Osmunda, called ‘‘ flowering-fern’’ also practices 
division of labor, but practices it less completely, 
for the lower part of the great frond is green and 
leaf-like, while the upper portion is a plumy mass 
of densely-crowded sporangia. 
The development of these sporangia begins in 
early spring, before the fronds unroll, and they 
attain their full growth by the first of June. So 
the royal Osmunda takes more than a month’s pre- 
cedence of less methodical ferns, which make all 
fronds serve both purposes. 
The sporangium in all the true ferns is formed 
from a single superficial cell. This cell grows so 
as to project above the general surface of the 
frond, and when it is hemispherical it is cut in 
two by a crosswise partition. 
The inner section will become the stalk of the 
sporangium, and the rounded outer portion will 
eventually be fashioned into the sporangium itself. 
But in the adder’s-tongues and some other fern- 
