PYCNIDES OF CRUSTACEOUS LICHENS. 209 
In many cases they evade detection by the lens unless previously soaked with moisture, 
which renders them turgid, brings out their form if papillate, and develops any contrast 
-of colour that may exist between them and the thallus. In all cases the addition of 
water (allowing it to be thoroughly absorbed) renders spermogones and pycnides more 
apparent and more easily examinable; and in all cases I so applied it. Its necessity was 
specially apparent in such cases as the following :— 
The genus Pertusaria. 
Many species of Lecanora :— 
Ez. Lecanora glaucoma. | Lecanora callopisma. 
cinerea. 
Many species of Lecidea :— 
Ez. Lecidea parasema, no. 13. Lecidea quernea, no. 2. 
| contigua, no. 4. 
albo-atra, nos. 2, 6. 
abietina, no. 11. | ——— uliginosa. 
minuta, no. 2. | 
Many species of Endocarpon :— 
Ez. E. fluviatile. 
6. The spermatia are among the smallest that occur in lichens—frequently atomic, and 
scarcely discernible from mere granules or cell-nuclei. 
Ez. Endocarpon pusillum, no. 2. 
7. The spermatia occasionally so closely resemble paraphyses or raphides that they are 
apt to be overlooked. | 
Ex. Lecanora glaucoma. 
8. The spermogones are frequently (apparently as a concomitant of age) abortive or 
degenerate, and contain no distinct sterigmata, nor spermatia, by which they can be, even 
approximately, determined. 
Ex. Lecanora tartarea. Ez. Lecidea coniops, no. 8. 
atra, nos. 8, 9 sublurida. 
Carrollii. epigæa. 
Lecidea fusco-atra, nos. 3, 6. sanguinaria, no. 1. 
rivulosa, no. 4. Verrucaria gemmata, no. 10. 
glabrata, no. 1. 
parasema, no. 10. 
contigua, nos. 2, 5. 
Both my memoirs relate mainly to the minute anatomy of the spermogones and pyenides 
of lichens. But in making the thorough examinations requisite for the detection of 
these organs and the exposition of their structure, I incidentally met with many points 
of interest in the minute anatomy of the apothecia and thallus; with many features in 
the general morphology of lichens bearing on their classification; and, in short, with 
many phenomena elucidating obscure points im the general natural history of lichens. 
Notes on the general phenomena just mentioned have been incorporated in both 
memoirs. 
