250 DR LAUDER LINDSAY ON THE SPERMOGONES AND PYCNIDES 
When mature, they are generally seen each to be pierced by a minute ostiole, which, 
with age, becomes very patent and large. When moistened, the spermogones 
become semi-translucent. The envelope is deep-brown. The spermatia are 
minute, rod-shaped, seated on the apices and sides of articulated sterigmata, whose 
component cellules have very thick walls. 
Specimen 2.—On granite, coast of Cork; coll. CarroLL; with apothecia. The 
spermogones are here also plentiful as small brown papilla, grouped generally in 
twos or threes, sometimes confluent, and then very irregular in form. The older 
ones.are marked by their large irregular gaping ostioles, which give the lacinize the 
appearance of being studded over with a series of perforations. The spermatia are 
rod-shaped, about sth long, and s;,0th broad; the sterigmata consist of a few 
shortish linear articulations. 
Specimen 3.—ScHARER exs. 565; on maritime rocks, coasts of the Atlantic; 
Pretvet. There are a few young or mature papilleform spermogones; but the 
majority are old, with large irregular ostioles. The latter, in many cases, from 
falling out of the body of the spermogone, have become saucer-shaped or cyphel- 
loid—the base of the cavity being deep-brown, and the edge very irregular. These 
cyphelloid ostioles are generally visible to the naked eye. The spermatia are 
about mth long; the sterigmata sth to jth long. 
Species 13. P. parietina, L., 
A beautiful and familiar plant, having a very wide geographical range, as it 
occurs in Europe, Africa, Asia, Northern America, Chili, Polynesia, and Australia. 
In this, and the species which follow, the spermogones are cones or warts of a 
yellow or reddish colour; but internally, their structure is that of the spermo- 
gones of the Physcie already described. P. parictina is the type of a section of 
Physcia with a Parmeliiform thallus of a yellowish colour—a section which in- 
cludes P. candelaria, P. flammea, and P. chrysophthalma. The spermogones of 
P. parietina are minute cones or tubercles, scattered about the periphery of the 
thallus, outside the region occupied by the apothecia. They are of an orange-red 
colour, deeper than that of the apothecia, and are generally more or less easily 
seen under the lens. They are usually in groups of two or three, seldom aggre- 
gated in large numbers. Their diameter is about ;;th; that of their ostiole, which 
is usually minute, round, and imperceptible, from about sth. The body of the 
spermogone is a spherical mass of a hard, dense, whitish tissue, immersed in the 
medullary substance of the thallus. The envelope is composed of delicate, cubical 
cellules, resembling those which make up the cortical layer of the thallus. The 
sterigmata are ramose and very irregular ; they consist of numerous short, roundish, 
or cubical cellules, originally having thin walls, which, however, in progress of 
growth, become almost solid, from thickening deposits on their interior. The 
spermatia are rod-shaped or sub-ellipsoid, and about sth to wooth long. 
Specimen 1.—Kinnoull Hill, Perth, March 1856, W. L. L.; with abundant 
