206 DR. LINDSAY ON THE SPERMOGONES AND 
of lichen-paraphyses. Thus, according to Nylander, those of Thelocarpon Laureri, Flot., 
are often ramose and contain oi-drops. In some cases at least they would appear to be 
simply hypertrophied, sterile sterigmata ; and perhaps in all cases they are to be regarded 
in this light. They are most manifestly so when they are not much longer than the fer- 
tile sterigmata, and are of similar form, though differing in length and sterility. They are, 
on the other hand, least evidently so when they form a network, by anastomosis, that occu- 
pies the whole interior of the spermogone, obscuring the fertile sterigmata. Occasionally 
the same filaments occur in pycnides, one of the many features in which (as formerly 
explained *) these organs resemble spermogones. "Thus these filaments occur equally in 
pyenides and spermogones in the same species in Lecidea Griffithii, nos. 3,7. The sper- 
mogonal filaments in question are to be found equally in the higher and lower lichens. 
Among the latter, illustrations may be met with in :— 
Lecanora cinerea, where they are arti- Lecidea flexuosa. 
culated. ——— glauco-lepidea. 
——— cinerea var. atrocinerea. geographica. 
—— atra. Opegrapha varia, no. 2. 
subfusca Arthonia gregaria. 
varia, no. 6. Stigmatidium crassum, no. 3. 
Pertusaria ceuthocarpa. 
Lecidea fusco-atra, no. 6. 
— — Ebrhartiana, no. 5. 
Verrucaria gemmata, nos. 6, 10. 
—— glabrata, no. 2. 
Calicium stigonellum. 
tenebrosa, no. 2. 
i 
Among the higher lichens they are granular and septate in Parmelia saxatilis (** Mo- 
nograph of Abrothallus,” pp. 35, 36, pl. v. f. 4). 
II. Development of the fertile or ordinary Sterigmata. 
In some cases, at least, they were seen to arise from tubules resembling those of the 
medullary tissue of the thallus, from which they were given off vertically or at right 
angles as digitate processes f, just as the upright culms of sand-grasses or sedges are 
given off from the horizontal trailing roots. At other times and more generally their 
matrix was the cellular tissue constituting the inner wall of the spermogonal envelope, 
which tissue usually consists of small, frequently irregular, cells, closely aggregated, and 
of various shades of brown. 
III. Apparent absence of Sterigmata. 
In some cases, especially where they are linear or spherical in form, the sterigmata are 
so short, minute, and inconspicuous that they cannot be distinctly made out, the Sper- 
matia appearing to arise directly from the cellular tissue of the inner wall of the spermo- 
gonej. This is the case, for instance, in :— 
Lecidea parasema, no. 18. | Graphis scripta, no. 3. 
* Vide p. 202. T I noticed the same phenomenon occasionally in basidia. 
= A parallel phenomenon occurs occasionally, in pyenides, with the basidia. 
