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such pycnides as those of Peltigera , in which the contained 
corpuscles are the only reason for regarding the concep- 
tacles as pycnides rather than spermogones. But in certian 
lichens pycnides co-exist with spermogones of the ordinary 
character. 
b. That they are sporoid in function as well as form and gene- 
ral aspect. The strong argument in favour of this view is 
their germinative faculty. According to this view, pycnides 
may be regarded as secondary apothecia, or female organs, 
— and stylospores as secondary or supplementary spores 
It has been noticed that, in certain cases, there is a general 
resemblance in form between the stylospores and the spores 
of the same species ; but this, if not exceptional, is still far 
from being the general rule. 
12. Pycnides are much more common among the lower, or crus- 
taceous, lichens, than among the higher or fruticulose, filamentous, 
and foliaceous ones; while, on the other hand, the spermogones are 
most abundant and distinct in the latter. Pycnides would appear to 
be a connecting link between the lichens and the fungi, and we 
find them most frequent, perhaps, in species most nearly allied 
to the fungi. 
13. Pycnides may occur in plants or specimens bearing apothecia, 
but not spermogones; or they may occur alone, both apothecia and 
spermogones being absent ; or pycnides and spermogones, one or 
both, may occur in species seldom or never bearing apothecia, as in 
some species of Strigula. 
14. Pycnides, from their outward resemblances, are apt to be 
confounded with, or mistaken for, — 
a. Spermogones. 
b. Minute Verrucarias. 
c. Minute parasitic fungi, for which, indeed, they have hitherto 
been almost universally mistaken. Pycnides resemble the 
fructifications of fungi, called by the older mycologists, 
Diplodia , Phoma , Septoria , Cytispora, Sclerotium , Mesal- 
mia , Phyllosticta , and Polystigma. 
15. A few lichens, — especially crustaceous ones, — possess several 
forms of spermogones, or of pycnides, or of both, —though such a 
phenomenon is comparatively rare. This is just what occurs in such 
fungi as Erysiphe , which has five several forms of reproductive 
vol. iv. 2 a 
