X 
PREFACE. 
straightness or curvature 
ters the character of the 
example the varieties of the 
cornu, f. 770, and variabile, 
Ferns.” The division of 
in varieties of the Female 
of the common Polypody, 
gantissimum, (fig. 1, plate 
Fig. 3. 
of which greatly al- 
frond. Compare, for 
Hart’s-Tongue, Cervi 
f. 643 of “ Our Native 
the Rachis is marked 
Fern; and, in a form 
so well-named P. ele- 
trace of the normal 
1) all 
character of the species is lost, except that the sori are 
the same — a circumstance for remark — the much less com- 
pound form, Polypodium Cambricum, a pinnule of which 
we figure (fig. 2, plate 1) producing, we believe, no 
spores. A more interesting feature in the Rachis is the 
vegetation of new plants from its termination as well 
as from the axils of the pirmse along its whole course. In 
Polystichum angulare proliferum, var. Crawfordii, scaly 
bulbs bearing frondlets may be seen thus produced both 
from the summit and sides of the main stalk. But in 
several exotic species of Asplenium Cystopteris and Aspi- 
dium, as well as in the curious Fadyenia and in Campto- 
surus, perfect plants are habitually produced both with and 
without contact with the soil at the extremity of the Rachis. 
