122 DR LAUDER LINDSAY ON THE SPERMOGONES AND PYCNIDES 
the spermogones of Usnea would appear to have been noticed by Dr Nynanper of 
Paris, who, however, has as yet given no full or precise account thereof. 
These spermogones are tubercles or warts, varying greatly in size and form, 
which are scattered abundantly (when they occur at all) along the ultimate ra- 
muscles of the thallus, near their tips especially. To these they give the very rugose 
or warted appearance, which they not unfrequently bear, especially in var. hirta. 
They occur sometimes also on the cilia, which diverge from the margins of the 
large flat apothecia. They are, as I have already stated, concolorous with the 
thallus, and the ostiole can rarely be detected, unless when it is, as is seldom 
the case, black-punctate. Their nature, however, can be readily determined by 
placing one or two of them in a drop of water between glass slides under the 
~ microscope, while subjecting them to moderate pressure. The emission of myriads 
of small needle-like spermatia will at once remove all doubt as to their nature. 
Sometimes the spermogonal warts are isolated; more frequently they are confluent 
and irregular. Their cavity, too, though sometimes simple, is generally sinuous 
or compound, branching into numerous narrow compartments. Externally, the 
spermogones of Usnea resemble those of Aamalina, which are somewhat better 
known and more abundantly met with. The sterigmata, which converge towards 
the centre of the spermogonal cavity from its internal walls, are either simple and 
linear, or composed of a few linear, delicate cells or articulations, as in many 
Parmelie. These cells bear, on their apices, rod-shaped spermatia, varying from 
woth to auth long, and having a breadth of about yacth. Associated with the 
ordinary sterigmata are numerous elongated, ramose, delicate, sterile filaments, 
such as occur in Ramalina, and in several Parmeliw. NY LANDER describes the 
spermatia as rather thicker at one end, which thicker end is the one attached to 
the sterigma, and therefore lowest. This I have not specially noticed. The sper- 
mogones of Usnea are sufficiently and well illustrated by those of its species, 
U. barbata, which is to be found all over the world. . 
Sprcies 1. U. barbata, Fr. 
Specimen 1.—Var. hirta (or spermogcnifera, pro parte). Lrrcuton’s_ “ Lich. 
Brit. exsice.” No. 1. (Engl. Bot., Plate 1354). Haughmond Hill, Shropshire. 
On the two right-hand specimens in my copy, both of which are dwarfed, de- 
formed, much warted, and of a very dark greenish-gray colour: in fruit. In one 
specimen the spermogonal warts are chiefly scattered over the cilia, proceeding 
from the margins of the apothecia; in the other they cover the sterile ramuscles, 
especially about their extremities. In site and external appearance the spermo- 
gones are extremely like those of Ramalina scopulorwin, Ach., and R. polymorpha, 
Ach. They are generally confluent, large, and irregular, and are among the most 
distinct spermogones | have ever observed in this genus. Their envelope is com- 
posed of hexagonal or roundish cells, constituting a tissue resembling that of the 

