THE ROCK SPLEENWORTS. 
HE spleenwort family is one of 
the dominant fern families of 
the world, and is represented 
in eastern America by more 
species than any other. A 
strong family resemblance runs 
through them all, though they 
present few of the problems in 
identity so common in other 
a” ferns. The young collector 
oa will vote them very satisfactory 
to study. Asa group they may be recognised by their 
bearing sporangia in linear sori that are covered with 
indusia fixed by their inferior sides and opening toward 
the midrib. In size and habitat the species fall into two 
fairly natural groups, the small ones being all rock-loving 
plants and the large ones preferring to grow in rich 
earth. The rock spleenworts will be treated of in this 
chapter. 
The Maidenhair Spleenwort. 
The dainty little maidenhair spleenwort (Asplentum 
Trichomanes) although not the smallest of the Asplenzums 
is the smallest of our common ferns. After the poly- 
pody, it is probably the most abundant of all the strictly 
rock-loving kinds. It prefers the nooks and shelves of 
dryish, shady cliffs where it roots in the smallest crevices 
