PYCNIDES OF CRUSTACEOUS LICHENS. 205 
classifiers is to trust too implicitly to the characters furnished, or supposed to be fur- 
nished, by individual organs or phenomena, be these apothecia, thallus*, spermogones, 
or colorific reaction. The fallacies of characters founded on colour-reaction suffice to 
illustrate those appertaining to other generalizations of living systematists of chief 
reputet. 
The earlier lichenists—those who flourished before the use of the microscope rendered 
it possible to determine the nature of the tured not only varieties 
and species, but even genera, out of spermogoniferous conditions of lichens}. Thus many 
species of the pseudo-genera Pyrenothea, Cliostomum, Thrombium, Rhytisma, Limboria, 
Septoria, Phoma, and others consisted simply of the spermogones of dicecious lichens, in 
which these organs occurred «alone, unassociated with apothecia. By reason of their 
growing alone, or of their number, grouping, site, or other characters, spermogones not 
unfrequently give a particular facies to a lichen; and even at the present day such con- 
ditions are by systematists, in their irrepressible love for name-giving and species-making, 
raised to the spurious rank at least of varieties, with distinctive names$. Similar pseudo- 
varieties are seldom made from pycnidiferous states by lichenologists || ; but I have little 
doubt that lichen-pyenides, occurring by themselves, are familiar to fungologists as 
supposed species of pseudo-genera, such as Septoria and Phoma. I have equal reason 
to believe that spermogoniferous conditions of lichens are occasionally mistaken by fungo- 
logists for pseudo-species of Fungi. 
Additional points of interest in Minute Anatomy, Morphology, and Physiology. 
I. Frequent occupation of the spermogonal cavity by elongated filaments that arise 
among and project beyond the ordinary fertile sterigmata. 
These filaments are usually very delicate, with a wavy or tortuous outline and a 
rounded end, which bulges more or less. They are generally hyaline, though occasion- 
ally coloured ; sometimes simple; more frequently they are ramose to various degrees, and 
sometimes they anastomose, so as to form a network more or less open or compact. 
Occasionally their interioris granular; or there are obscure, or pseudo, septa; or they con- 
sist of a series of distinct articulations, composed of linear cells of varying length. The 
development of these filaments appears to bear relation to the age of the spermogone, 
being found only in organs that are mature or old; and the exhibition of granularity or 
colour, or the development of septa or articulations, may also be concomitant pheno- 
mena of age. "There is a certain parallelism (on which, however, obviously no specula- 
tions as to function can be as yet safely based) between these filaments and some forms 
* Were we to classify or name by the single character of the spermatia, we should be led into the same error as 
when that of the sporidia is adopted, viz. to separate forms, that obviously belong nevertheless to a single type or 
species, into different species or genera; and, on the other hand, to combine in the same genera or species lichens 
having otherwise the most diverse charaeters. 
t Vide the author's papers on ** Chemical Reaction as a specific Character in Lichens,” Journal of Linnean 
Society, Botany, vol. xi. p. 36; and Trans. Botanical Society of Edinb. vol. x. p. 82. 
t Illustrations may be found in Lecanora cinerea, L. aurantiaca, no. 5, and Lecidea Ehrhartiana. 
§ Vide summary of characters of spermogones and pyenides in Edinb. Royal Society Proceedings, p. 178. 
|| According to Nylander, Strigula melanophthalma, Mont., is only a pyenidiferous condition of S. complanata,Mont. 
VOL. XXVIII. 26 
