GENERA AND SPECIES. 125 
great masses, from which portions have to be torn. The 
fronds do not develop the fruit until they have been ma- 
ture for some time—apparently not until they are at least 
a-year old, perhaps older. Then the ends of the veins en- 
large and grow beyond the margin of the frond. A season 
is occupied in developing the first cluster of spores. At 
the end of the second year the frond has borne some fruit; 
but the process of fruit-bearing continues for several sea- 
sons. The bristle, upon the base of which the sporangia 
grow, continues to develop, its base always covered with 
new sporangia. ‘This bristle, when not broken off, becomes 
half an inch or more in length. By means of a sufficiently- 
high magnifying power the scars left on the bristle by the 
breaking away of the foot-stalks of the sporangia may be 
plainly seen. We can not tell how many years a single 
frond of Trichomanes radicans may live. It must exist 
five or six years, possibly more. It is difficult to command 
the conditions necessary to make it grow in cultivation. It 
will remain in a natural condition many months under a 
moist bell-glass, if aired occasionally to prevent molding. 
In 1877 I gave a portion in a fresh state to ‘William,’ a 
guide at the Mammoth Cave, to plant near the mouth of 
the cave, and I have since learned that it is doing well.” 
Mrs. Yandell brought a few plants of this fern from 
Laurel County, two summers ago, and placed them in a 
pot filled with fibrous peat and sand. I have this fern in 
my possession, and it continues to put out new fronds. 
The vase is covered with a bell-glass, and is kept shaded 
from the sun’s rays. 
