112 
Mycologia 
a lichen is a lichen whether this external portion be much or little. 
We must consider the whole structure, the parts that grow on 
the hepatic as well as those that grow in the algal mass, a very 
primitive lichen. The undetermined point of special biological 
interest regarding the fruiting is whether the apothecia are ever 
produced before the relation with the alga is established. It mat- 
ters not that the apothecia are sometimes formed at some distance 
from the algal colonies, for the nourishment could be carried by 
the hyphae. In Engler and Prantl, Lindau (82) gets this plant 
instead of Zahlbruckner, and places it near Bulgaria. Rehm 
(103) agrees with Lindau regarding the position; but Rehm 
believes that lichens might well be distributed among other fungi 
and frequently treats lower lichens with other Ascomycetes. So 
his stand is not proof that he does not regard this plant a lichen. 
Gloeopesisa rehmii Zuk., another of Zukal’s half-lichens (152), 
produces its apothecia at a distance from the Gloeocystis or the 
Palmella masses, into which certain hyphae penetrate and very 
probably convey nourishment to the points where the apothecia 
are developing. Zukal says that this lichen passes its early stages 
as an epiphyte, but not as a parasite, on the leaves of Junger- 
mannia triophylla; and it would be especially instructive to know 
certainly whether the apothecia ever develop before the algal 
colonies are attacked. Rehm (103) places this lichen with the 
Bulgariaceae, but Lindau (82) considers it one of the Pezizaceae. 
Very different are the conditions in Nectria phycophila Zuk., 
another of Zukal’s half-lichens (152), which grows in Hypheo- 
thrix zenkeri, of the Oscillatoriaceae. The mycelium of the lichen 
is found in the trichomes of older dead portions of the algal 
colony; but, in younger portions of the colony, the hyphae occur 
in the sheaths only. No haustoria were noted; but this fungus, 
recognized as a Nectria by Lindau (82), is as good a lichen as 
are Ephebes or Collemas and other lichens in which the relation 
of the lichen to the alga is not very intimate. One who believes 
that the lichen consists of the fungus and the alga which grow 
together can not consistently place this or any lichen with fungi ; 
so this plant can not properly be regarded a Nectria by them. 
Yet, this inconsistency did not occur to Zukal, who regarded the 
lichen a dual organism; nor does it seem to have troubled many 
