284 The American Naturalist. [April, 
indubitable fungus ancestor, the thelephora; on the other, the 
two direct descendants, Cora, and Dictyonema, incipient phyla, 
whose future directions of development are foreshadowed in 
the Laudatea-forms. 
The ascolichens were derived from the Ascomycetes at an 
' earlier period, and their great specialization and the interval 
of time elapsed have to a considerable degree obscured the 
points of departure. But, as has been pointed out above, the 
“ fungo-lichen” genera, Caliciwm, Bilimbia, Bacidia, Placogra- 
pha, Melaspila, Biatorella-Biatoridium, Patinella-Lecidea, Buellia- 
Karschia, Graphis-Hysterium, and the species, Buellia myrio- 
` carpa, leave little doubt concerning the derivation of their 
corresponding families. They simply await the thorough 
investigation given hymenolichens by Moeller. If we are to 
consider only the highly specialized ends of phylogenetic 
branches, we should all be constrained to admit that lichens 
must receive treatment as a group. But, in such an event, we 
should do the greatest violence to phylogenesis as the deter- 
minant in taxonomy, in making lichens codrdinate with alge 
and fungi, merely on the basis of a physiological character. 
I admit that there could bea class, or a branch, Lichenes, based 
upon this physiological character, or perhaps upon morpho- 
logical characters induced by adaptation to assimilation-pro- 
cesses. So, also, might there be a group, Parasitice, coördinate 
with Phanerogamx, which would include such closely related 
genera as Cuscuta, Razowmofskya, Phoradendron, Thalesia, ete. 
Such is the logical result of Reinke’s opinion that a more or 
less constant physiological character, for lichens, “ consortism,” 
obtains for the delimitation of great groups, in spite of the 
significant evidence of phylogeny. 
Summarizing: Reinke’s conclusion that lichens are physio- 
logically and morphologically distinct from fungi is untrue, 
and his statement that it is impossible, on account of certain 
physiological characters, to distribute them among fungi is 
equally unwarranted. 
