122 
Mycologia 
old apothecia of many lichens; but they seem to be especially 
characteristic of pyrenomycetous lichens, particularly those that 
have muriform spores. Stahl (124) found them in Endocarpon 
piisillum Hedw. and in Polyblastia rugulosa Mass, and proved 
that, in these lichens, they are ejected with the spores, which soon 
germinate and attack the algae. Little is really known about the 
frequency of occurrence of hymenial algae at the time that spores 
are ejected; but it is probable that this is not uncommon in those 
pyrenomycetous lichens which are not able to live a considerable 
length of time outside the parasitic relationship with an algal host. 
Hymenial algae perform somewhat the same role as the algae in 
the soredia of higher lichens ; and since they occur in lower 
lichens, while the soredia are more common in higher lichens, each 
of these provisions for reproduction supplements the other. 
Even in lichens that have neither soredia nor hymenial algae, 
there is no difficulty about reproduction through lichen hyphae 
coming in contact with algal host cells. Since spores blow long 
distances, this could happen whether lichens grow near the algal 
hosts or not. 
These various observations regarding lichens growing in prox- 
imity with their algal hosts prove that lichens may frequently 
originate from spores which germinate and attack free algae; and 
it must be borne in mind that the spores may remain dormant for 
a considerable length of time until conditions favorable for 
germination are at hand. Such observations also show that both 
the algae and the lichens may grow separate from each other, the 
former throughout their whole life and the latter sometimes 
during a considerable time, very probably years in some instances. 
Such results make the consortium hypothesis wholly invalid, and 
seem to have been overlooked, underestimated or misinterpreted 
by those who hold to that hypothesis. 
Cultures of Lichens With or Without the Algal Hosts 
Alfred Moller (87) cultivated Lecanora subfusca (L.) Ach., 
Thclotrema lepadinum Ach., Pertusaria communis Lam. and DC., 
Graphis scripta (L.) Ach., Buellia punctiformis (Nyl.) Hoffm., 
Lecidea enteroleuca Ach., Opegrapha subsiderella Nyl., Arthonia 
