6 
Ohio Biological Survey 
plant. The genus Mycocalicium, of the Caliciaceae, has been segregated 
from Calicium to receive members which do not live with algae. Sclero- 
tinia tubcrosa is known to live rarely in parasitic relation with an alga 
(Synes58). Some of the Cclidiaccae are algicolous, others not. 
Agyrhim riifum has been considered both lichen and non-lichen. The 
species of Lccideopsis seem to be partly lichens and partly non-lichens. 
Tobler’s study of Phacopsis vulpina (62) proves that this plant is a lichen, 
and the species of Conida and Celidium await similar study. The Patel- 
lariaccae present similar conditions in that the genera KarscJiia,Biatorella, 
Lcciographa, and Melaspilea all contain some algicolous and some non- 
algicolous ascomycetes. Among the Lecanactidaceac are species which 
are non-algicolous. Zukal’s investigation (67) has shown that Pariiphrd- 
dria heimerlii and Geopcma rehmii of the Cenangiaceae are both 
algicolous, though other members of the family are non-algicolous. Some 
species of Dichaena are supposed to be lichens, while other members of the 
Dichacnaceae are not. The lichen genus Arthonia is well known to con¬ 
tain non-lichen species and other species that are non-algicolous during 
part of their lives. The same condition is found in the lichen genera 
Graphis and Opegrapha (Frank 33), and no one knows how many 
species are non-algicolous during part or all of their lives, or how many 
other genera of the Arthoniaceae and the Graphidaceae contain both lichen 
and non-lichen members. Further statements regarding forms transi¬ 
tional between lichen and non-lichen ascomycetes will be found in a 
previous paper (Fink 31), and only extended biological research will 
give definite knowledge of hundreds or perhaps thousands of such plants 
which are poorly understood. 
The research on the sexuality of ascomycetes is all comparatively 
recent, nothing of importance dating back of 1863 (De Bary 3). The 
whole literature of the subject is readily available and is convincing with 
respect to the rather close relationship among all undoubted ascomycetes. 
The lichens that have been studied, except those that are degenerate with 
respect to sexual reproduction, show the Collema-Mke type of female 
reproductive tract, which is very similar to that found in some other 
ascomycetes that have been studied. Likewise, most lichens and other 
ascomycetes agree in that they develop similar ascocarps, simple or com¬ 
pound. It is admitted that the topography, the cytolog}-, and the full 
development of the sexual reproductive tracts and the ascocarps are not 
completely known in any of the species that have been studied, and a 
large amount of research is still necessary before we can hope to approxi¬ 
mate a natural classification of ascomycetes. The nuclear behavior is 
