



14 THE BRITISH FERNS. 
vernation being plicate. The more compound of the eireinate species 
have not only the frond as a whole, but its divisions also, rolled up in 
a similar manner ; in such cases, the larger divisions first open, and the 
rest follow in succession. In many species, the fronds, when partially 
developed, have a very peculiar and graceful appearance. 
When the fronds become fully developed, two parts, the Stipes and 
the Lamina, are distinguishable. The stipes is the stalk, the lamina 
is the dilated leafy expansion. 
The stipes or stalk, sometimes by error called the stem, which 
latter term properly belongs to the caudex, is formed of a hard, 
external layer, covered by a cuticle, and enclosing a mass of cellular 
tissue, traversed by plates or bundles of vascular tissue, disposed in 
some regular order. The number and position of these vascular 
bundles have been considered sufficiently constant and important to 
afford characters for discriminating genera and species, but for this 
purpose they are valueless, as they differ in the same plant at 
different elevations of the stipes, as well as in stipites of different 
degrees of vigour at points of equal elevation. The lower part of the 
stipes, generally, and sometimes even the entire length of the Rachis 
—which is the continuation of the stipes through the leafy portion of 
the frond, is more or less furnished with paleaceous or membranous 
scales. These scales, which are generally brownish, are in some 
cases confined to a few small bodies scattered sparingly near the 
base of the stipes, but in other instances are so large and numerous 
as to produce a shaggy surface. They are, no doubt, appendages of 
the same nature as the hairs and scales found on the surface of 
other plants. Their form, as well as number and position, and even 
colour, are found to be tolerably constant in the different species 
or varieties, and hence they sometimes afford marks of recognition. 
Whenever they are produced along the rachis, as well as on the 
stipes, they are invariably largest at the base, and become gradually 
smaller upwards. In most of the rhizomatous Ferns, the base of . 

