TJie Status of the Algo-Lichen Hypothesis. 7 
neither adnate to or penetrated by the hypha3, but only adherent to 
them by the lichenin. ... In all cases the apparent union is 
■simply amylaceous adherence, and the fancied penetration the result 
of erroneous observation." He says that Stahl's observations are of 
no account, as he is a very careless observer, etc. 
Koerber, who is one of the best of observers, while he opposes 
Schwendener, admits that "'the germinating spores must have free 
gonidia belonging to the same species in order to develop a complete 
thallus," but that ''these gonidia are not algge belonging to thelich- 
•ens as a fungus, but gonidia previously separated from the thallus 
and which have become ' asynthetic. ' " He practically admits the 
' whole thing. 
Hartog says, speaking of Crombie's arguments, that he either 
utterly ignores the strongest points in favor of " Parasitism '* or 
laughs at them and says ''improbable," or that they are the result 
of " poor work " and '• erroneous observation.'' To use a favorite 
Cookian phrase, both Cooke and Crombie answer many of the 
best arguments in favor of " Dualism of Lichens " simply by " rhet- 
oric." 
It is a noticeable fact that in a new country where new groves of 
trees are being planted, before the trees show any signs of lichens 
they are covered, especially on the north side, by "green slime," and 
the thicker the " green slime " the more rapid is the growth of the 
lichens when they do appear. Again, it is noticeable that when lich- 
ens begin to grow on fences and trees they take the dampest, cool- 
est, shadiest places first, and gradually, if it all, extend to the dryer 
places, as seen on fences where boards cross the posts, where the 
lichens may be seen to extend a short way from the post along the 
centre of the board, avoiding the dry, windy edges. Our largest 
lichens are almost always found in the darkest woods. These facts 
show that lichens in general are not the " lovers of light, dry places," 
as one author claims. But on the contrary, while they do not choose 
such places as do the saprophytic fungi, they generally choose places 
where plenty of the lower algge are to be found. 
Most of the botanists who have made any experiments with spores, 
gonidia, and algae have obtained results conclusive enough to con- 
vince them that Schwendener is right. 
In conclusion, we now have lichens belonging to the Ascomycetes, 
the Hymenomycetes, and the Gastromycetes, according to most of 
our latest and best authors. The gonidia are pretty conclusively 
proven to be algae, notwithstanding Crombie's " rhetoric ;" and the 
