INTRODUCTION. 
And first, of the more common fibrous radicles, of which it is rare that any individual Fibrous 
of the genus is entirely deprived. It is true that, in plants which are upright in their Uools ' 
growth and very densely crowded together, such as J. Taylori and .7. compressa, they 
are discoverable only by means of a very careful examination. In some specimens 
of J. pinguis (tab. 46) alone, I have been unable to discover any vestige of roots ; but 
these were floating on the water. For the most part they have their origin on the 
underside of the stem or frond, in those species which are destitute of leaves, and always, 
in these, originate upon the nerve, if the plant have a distinct nerve. If otherwise, as 
is the case in J. epiphylla and J. pinguis, they grow indifferently from various parts of 
the lower surface. 
The highest powers of a microscope have enabled me to discover no peculiarity Structure, 
of structure in these fibres. They seem to be tubular throughout, never exhibiting any 
appearance of joints or constrictions, filiform, smooth, semitransparent, and of a very 
delicate membranaceous texture. In general they are colorless, or only tinged with 
light brown, which they might be supposed to derive from the soil on which they grow. 
J. pusi/la (tab. 69) is remarkable for the deep purple hue of its roots ; and those of J. excisa, 
J. hyalina, and J. ventricosa, not unfrequently partake the same tint. 
Upon the stipulaceous species of Jungermannne, the roots generally grow in bundles, Insertion, 
originating immediately beneath the stipules. In the exstipulated, they are thrown out 
indifferently, and in a more scattered manner from any, or every part of the stems and 
branches; even from those branches proper to the fructification, as in J. trilobata (tab. 76), 
J. setacea (tab. 8), &c. Even the calyx of J. Trichomanis (tab. 79), from its upper part, 
sends forth a few radicles ; but the hairs which invest this calyx must not be mistaken for 
roots ; since their direction is upwards, whereas that of the roots is always descending. 
I have said that the origin of the roots, in most instances, is on the stem. As in the 
Mosses, so in the Jungermanniae, an instance occurs of these roots proceeding from the 
leaves, as may be seen in J. complanata (tab. 81). 
In J. platyphylla ( Suppl . tab. 3) an example is found of the fibres being united in 
close fascicles, so as to appear like one thickened root. What I have described as such, 
I am now inclined to consider fiagella, of a similar nature to those that are seen on 
J. trilobata (tab. 76) ; and, indeed, I have observed some appearance of foliaceous scales 
upon two or three individuals. 
Mr. Lyell has directed my attention to a singular inflation at the lower extremity of 
many of the radicles in J. anomala, twice or thrice the diameter of the radicle itself, and 
which 1 am disposed to look upon as a disease in that part. 
Roots of the larger kind, hinted at in the beginning of this section, occur rarely. Radices pri- 
We have instances in J. Francisci (tab. 49), J. asplenioides (tab. 13), J. decipiens (tab. 50), mord,ll ' s 
J. Hookeri (tab. 54), and in J. emarginata (tab. 27). In the second, third, and fourth of 
these species, these roots creep horizontally ; in the rest they descend, and are sometimes 
branched, often themselves sending forth fibrous radicles. In all these there is no difference 
in structure from the stems ; but their color is paler, generally whitish, and they are very 
succulent. 
