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IL Memoir on the Spermogonesfand Pycnides of Crustaceous Lichens. , 
By W. Lauper LiNpshy, M.D., F.R.S.E., PLS. 
À | (Plates VIII-XV.) 
! Read June 16, 1870. 
WHEN, in 1859, I presented to the Royal Society of Edinburgh a * Memoir on the 
Spermogones and Pycnides of Filamentous, Fruticulose, and Foliaceous Lichens” *, I 
promised to complete my survey of Lichen-spermogones and pyenides by submitting a 
second or complementary Memoir on those of Crustaceous species. The memoir now 
offered is the fulfilment of that promise. It does for the Lower lichens what its prede- 
cessor did for the Higher: so that the two memoirs may be regarded as the halves of 
one whole, which takes a general survey of what have been called, in relation to the 
apothecia, the Secondary Reproductive organs of lichens. 
So regarding the two memoirs in question, I have for the sake of uniformity, with 
certain trivial exceptions to be immediately specified, retained in the present memoir the 
general arrangements of the former one. Thus I have used the same micrometrical 
notation; and the same nomenclature—in the case of spermogones, pyenides, sterigmata, 
spermatia, and stylospores. Considering, howeyer, the close alliance between lichens and 
fungi, to be hereafter More particularly adverted to—I have adopted the nomenclature 
of Fungologists,—Basidia, Sporidiat, and Asci—for Sterigmata (of pyenides), Spores, 
and Thecæ—in lichens. Mainly for economy of space, I have in the present memoir 
omitted certain matters that did not appear strictly relevant to my subject—such as geogra- 
phical distribution. And for the same reason I have confined myself mainly to the results 
of my own researches. 
As in the former case, the present memoir contains only the positive results of many 
hundred careful and laborious microscopical examinations. The study of the secondary 
reproductive organs of the lower lichens is, however, much more intricate and difficult 
than their investigation in the higher groups; and the proportion of negative results in 
the search for spermogones and pycnides is correspondingly greater. To what extent, or 
in what sense, this is the case can only be estimated or understood by those who have 
personally engaged in this obscure field of research. 
Neither of my memoirs pretends to give a systematic description of the spermogones 
and pyenides of all the known lichens either of Britain or of the world. Even were this 
a work that could be properly undertaken by an individual observer, it would occupy an 
amount of space disproportionate to the value of the result. All that I have aimed at 
or attempted is to present a series of illustrations or types of the various predominant 
forms of the spermogones and pycnides of lichens, with their contained corpuscles—a 
* Transactions, vol. xxii. p. 280. — Proceedings, vol. iv. p. 174. 
+ Vide author's paper on “ Parasitic Micro-Lichens.” Reprint from ‘ Quart. Journal of Microscopical Science, 
Jan. to Oct. 1869: p. 29, footnote *. À E 
VOL. XXVIII. os 
