: 8 pellucid, membranous, and flaccid ; while others are thick, 
. Sions being called lobes or lacíne. The general form of | 
E Pom. | QN GENERA AND SPECIES. 
FRONDS. 
Tue fronds before expansion are involutely coiled, in the 
manner of a watch spring, and gradually uncoil during 
the period of growth, and with a few exceptions have all 
their parts formed before they begin to unfold (definite), 
all of which increase in size with the progress of the frond. 
Fronds present extreme variation in size and form, vary- 
ing from less than an inch to 15 or 20 feet in length, and 
in form, from entire; like a blade of grass or ribbon to 
being compoundly divided. In describing them, the same 
terms are used as are applied to the leaves of flowering 
plants, that is, they are simple, entire, linear lanceolate, 
ovate, elliptical or sub-rotund, or they are pedate or pal- 
mately lobed, pinnatifid, or they are pinnate, bi-tripinnate, or 
more highly divided, and then termed compound multifid. 
They also vary considerably in texture, some being thin, 
fleshy, or hard and rigid. | 
In pinnate, bi-and-tripinnate fronds, the divisions (nt i 
detis) of the first are called pinn; and the second pin- 
nules, each of which individually represents a simple 
frond. The margins of simple fronds, and of pinne and 
pinnules, are either entire or variously dentate or sinuose 
. repand, regularly pinnatifid or otherwise divided, the divi- 
fronds, whether simple or in any way divided, is linear 
lanceolate, or oblong elliptical, or deltoid ; in deltoid com. 
pound fronds, the primary pinnæ assume the character of ` 
. branches, the ultimate divisions of which are often divided ` 
. into small lacinæ or dents, such being termed multifid. 
The axis of attachment of the pinne and pinnules is 
