196 DR. LINDSAY ON THE SPERMOGONES AND 
lichen-microscopists, and to the thorough character of their labours—many of these iso- 
lated spermogones and pycnides have been found so intimately associated with lichen- 
apothecia, that they are now generally regarded by lichenologists as belonging to the 
species to which the said apothecia themselves are to be referred. In other cases they 
have not yet been so correlated, though similar correlation is probably, in the majority, 
only a question of time and research. Itis obviously unscientific, on this account alone, to 
do what systematists are in the habit of doing in such cases to avoid a difficulty, viz. to 
assign them to unknown absent fungi, which, it is supposed, might have been associated, 
and may be in other cases. 
Both spermogones and pycnides appear occasionally to be erratic and parasitic ; they 
are aliens, whose usual associated apothecia or perithecia are known, but which occur 
on foreign structures, and must therefore be regarded as strays or waifs. Ex. Lecidea 
abietina, No. 12. 
Tt is another peculiarity of the spermogones and pyenides of the lower lichens, that 
they frequently occur directly on the bark of trees or on surfaces of rock or stone; on 
the substance or surface, that is, to which the thallus of the lichen, to which they belong, 
usually adheres when a thallus is present. The following illustrations occur in the 
present memoir :— 
Opegrapha atra, no. 4. Verrucaria biformis, no. 2. 
Arthonia astroidea, no. 1. Calicium tigillare. 
Verrucaria epidermidis, no. 3. 
Many of the lower or crustaceous lichens are destitute of a thallus, even though they 
usually or sometimes possess one. Here, again, systematists have been in the habit of 
assigning the athalline, and perhaps isolated, spermogones or pycnides to unknown absent 
fungi! The apothecia of the same lichens are, however, sometimes in the same athalline 
condition as their spermogones and pyenides; and it would be quite as philosophical to 
refer them to supposititious fungi. The biologist who patiently makes himself acquainted 
with all the life-phases of a lichen, recognizes spermogones and pyenides, as well as 
apothecia,—in their abnormal athalline condition—which are familiar to him in their 
normal, thalline state. But the mere systematist, whose aim is the discovery and naming 
of * new species," real or supposed, makes a very superficial examination (comparatively) 
of the secondary reproductive organs, if he examines them at all, and has consequently a 
very limited knowledge of their peculiarities. 
Again, it is extremely common in hand specimens for several species of lichens belong- 
ing to different genera, and each aecompanied by spermogones or pyenides, to occur on 
the same piece of bark or stone. They may further be intermixed in the most puzzling 
way, and they may be associated with fungi (such as Dichena rugosa, Fr.), whose sper- 
mogones or pyenides are sometimes similar. In these cases spermogones and pyenides 
do not necessarily belong to the lichens or fungi, with which they are most intimately 
associated. 
From these or other causes, it is frequently most difficult—if at all possible—to deter- 
mine whether given spermogones or pyenides belong to lichens, fungi, or fungo-lichens, 
and to what genera or species! Difficulties of this kind I constantly met with in my 
