16 
of the plant are neither more nor less than a fungus which has 
seized upon the Algse (a colony of them), made slaves of them, and 
indeed, established itself upon them as a parasite! But you will 
be eager to know if this teaching, this Fungus-alga theory, as it is 
called, rests upon any well-ascertained facts. In brief the evidence 
is this. Many fungi produce their spores in little asci or thecx or 
sporangia, and are called ascomycetous, ascosporous or thecasporous. 
The spores of /ichens are produced exactly in the same manner, 
and have no connection with the gonidia—therefore they appear to 
belong to the Fungus. Again the gonidia are said to be real 
Alge, some of them well-known to exist quite independent of the 
Lichen thallus. Mr. Crombie, one of our ablest Lichenists, 
vigorously supports his favorite plants in their claim to independ- 
ence. In maintaining that a lichen is a lichen and nothing else, 
he speaks of the Fungus-Alga theory (hypothesis) as “‘ the romance 
of lichenlogy.’’ He reasons strongly, and seems to prove that the 
gonidia, though like certain Alge, are not identical with them, and 
further, that the gonidia really have their birth within the cellules 
of that part of the plant known as the cortical layer. He deals 
with several other difficulties that confront the Fungus-Alge theory, 
but still the new creed gains ground, and is looked upon as the 
correct thing, for it finds a place in the most recent works of 
English and other authors. Now, though we cannot settle any 
knotty questions, we may learn something, by looking at a cross 
section of a lichen thallus, say a leaf-like one. There are three 
layers to be seen, namely, a cortical layer (just referred to) of cells 
with thick walls, then a layer containing a good proportion of 
gonidia, and then, underneath, a mass of long thread-like cells 
(called hyphz) from which false roots (rhizine) proceed. Lichens 
agree with their allies in not needing true roots, for it is chiefly 
the attachment they require. The noteworthy point in our section 
is this—the gonidia do not appear to be in real union with any 
other portion of the thallus, and but few men have asserted that 
there ever is such union between them and the so-called Fungus 
threads (hyphe). Crombie’s great point is that such organic con- 
nection between them and the cortical layer did exist, and was 
evident enough in the early stages of growth. If heis not accurate 
here, then the men of the modern theory may have a prima facie 
case, but they must accept as one of their ‘articles’? something 
that has no parallel anywhere in nature, and it is this—that tins 
cells work hard and maintain a great amount of life that ‘ hangs 
on,’’ not only without being destroyed, but even with great advan- 
tage to themselves. Crombie tells you that in all ordinary cases 
a fungus will either wound or slay the plant it lives upon, but the 
Fungus-Alga men find here a great exception to the rule. Professoy 
