214 DR LAUDER LINDSAY ON THE SPERMOGONES AND PYCNIDES 
Species 5. P. tiliacea, Ach., 
Which occurs in Europe, Africa, America, Asia, and Australia. BayRHOFFER 
regards this as the type of a hermaphrodite lichen. From observations on this 
and other lichens, he maintains the doctrine, that spermogones are transformed, 
in the progress of development, into apothecia. There is certainly nothing in 
this species to warrant such a conclusion. The site and structure alike of the 
apothecia and spermogones are different. But BayRHOFFER’s views on this 
and other departments of physiological lichenology are now generally regarded 
as speculative in the extreme,—as more ingenious than sound. They will be 
found freely criticised in the “ Flora” for 1851-2, as well as in TuLAsNnE’s 
Mémoire, p. 165, et seg. From the pale-gray colour of the thallus, the black 
punctiform spermogones of this species are generally easily recognised. They 
are usually grouped, sometimes confluent, studded about the margins of the 
lobes. ‘The internal tissue is dense, horny, and of a grayish colour, the cavity 
simple, but obliterated with age, the whole body of the spermogone becom- 
ing a nucleus or kernel of a horny tissue. The spermogone, in its mature and 
old state, particularly the latter, is easily enucleated by the point of a needle. 
The sterigmata are about ;,th to qth long, and zath broad; they consist of five 
or six delicate linear articulations. The spermatia frequently differ in length, 
according as they are fixed or free; in the former case they are sometimes 
soth to goth. in the latter, sath to sath long. 
According to NyLANnDER, P. carporrhizans, Tayl., is referrible to P. tiliacea. It 
may be so pro parte; but the majority of specimens I have seen are certainly 
referrible rather to P. sinuosa. 
Specimen 1.—Scu#®RER exs. 358 (sub nom. P. quercifolia a. munda,) on the 
trunks and branches of trees, Mount Laiigenberg, Switzerland. The spermatia 
and sterigmata of the black punctiform spermogones are among the most beauti- 
ful I have seen in the genus Parmelia. Some of the attached spermatia are captli 
to smth long, with a breadth of s;,th. Intermixed with the ordinary spermati- 
ferous sterigmata are numerous elongated, sterile, ramose filaments, as in P. sazxa- 
tilis, P. physodes, P. perforata, and other Parmelias. The free spermatia measure 
sth long; some of the spermatiferous sterigmata, with the spermatia attached, 
about =,,th. 
Specimen 2.—B. de Bigorre, Pyrenees, Spruce’s “ Lich. Pyrenzi;” in Herb. 
Hooker, Kew; with plentiful apothecia. The spermogones are generally crowded 
on the convexities, and about the ends of the lobes, of the thallus, each being 
perched upon, or rather contained in, a pale cone-like elevation of the thallus. The 
ostioles are marked by largish black points. The spermatia are needle-shaped, 
about znth long, and s,5th broad. The sterigmata consist of five or six linear — 
delicate cells or articulations. 

