PYCNIDES OF CRUSTACEOUS LICHENS. 195 
2. Pycnides instead of spermogones, where the latter usually or occasionally occur, in:— 
Lecanora subfusca, no. 18. Lecidea rosella, no. 1. 
—— milvina. minuta, no. 1. 
Lecidea parasema, no. 12. Opegrapha atra, nos. 1, 2. 
disciformis, no. 5. varia, no. 7. 
abietina, nos. 1, 2, 3, 4, 8, 10. Calicium eusporum. 
atro-grisea, nos. 3, 4, 5. 
^ 
Spermogones instead of pycnides, where the latter usually occur, in 
Lecidea abietina, nos. 6, 11, 12. 
In comparing the results of my own researches on spermogones and pyenides with those 
of Kórber, Nylander, Mudd, or other authors, relating to the same common, and frequently 
cosmopolite, species, the most remarkable discrepancies occur. Such discrepancies have 
been hitherto referred by systematists—who would appear to have an overweening 
confidence in their own infallibility, with a corresponding want of faith in the results of 
other observers of equal experience and skill—to 
Errors, either in observation or interpretation ; or in the determination of the family, 
genus, and species, whether of fungi or lichens. 
That error is likely to be committed, by even the most distinguished lichenologists and 
fungologists, in the study of a subject so intricate as that of spermogones and pycnides, 
will probably be granted by every one who has engaged to any extent in the said study. 
The sources of confusion or error are avowedly numerous and varied, including the 
following :— 
1. The frequent occurrence of spermogones or pycnides alone—that is, wnassociated 
with apothecia or perithecia, either of lichens or fungi. 
2. The frequent intermixture of several forms of spermogone and pyenide with the 
apothecia or perithecia of different species and genera, both of lichens and 
fungi. 
3. The frequent occurrence of spermogones and pyenides in an athalline condition. 
4. The frequent resemblance between the spermogones and pyenides of lichens and 
those of fungi. 
It is one of the many peculiarities of the spermogones and pyenides of the lower 
lichens that they often occur in patohes by themselves, unassociated with the higher, 
and more usual, forms of fructification either of lichens or fungi. In this condition they 
have been regarded and described—even within the microscopic era in liehenology—by 
lichenologists as species of a genus that is now, by common consent, abolished— Pyreno- 
thea. Thus they were so described and figured in Leighton's * Angiocarpous Lichens’ 
(1851). By fungologists, on the other hand, they were, or are, considered species of 
Septoria and other genera of fungi, some at least of which have been found to consist, 
like Pyrenothea, merely of the secondary forms of fructification of organisms belong- 
ing to other genera or species. Of late years, however, —thanks to the multiplication of 
