Organization of Coenogonium. 429 
Now it is precisely some filaments of this latter category 
that showed me, when I analyzed the above-mentioned species 
for its specific characters, a remarkably demonstrative case, 
which forms the subject of this note, and confirms the fine 
general results recently published in the splendid work of 
Dr. Minks. 
This filament for a great part of its length measured 8 pu 
in diameter, and consisted only of the large green tube. It 
agreed with the large green tube of the other filaments of the 
same clump, the greater number of which were loosely covered 
or coated with a small number of slender hyphoidal filaments. 
It therefore contained the cylindrical green gonidia, which 
simulated the joints of a conferva; it was the alga of the 
theory. But at a certain point this large gonidiophorous tube 
became suddenly constricted, in the form of a cone a little 
longer than broad, and afterwards continued in the form of a 
very slender capillary tube, only 2 in diameter, without 
there being any discontinuity of ne cavity between the large 
tube and the very slender part. ‘lhe whole was formed only 
of a single cell, at first wide, and afterwards very narrow ; 
and the narrow part was comparatively hyaline, and in other 
respects perfectly agreed with the slender hyphoidal tubes of 
the theoretical fungus, which cover the large green tube or 
theoretical alga in other filaments of the same species. More- 
over the narrow part, when examined with powerful immer- 
sion objectives, and with the assistance of Prof. Abbé’s hght- 
condenser, showed clearly the microgonidia, the gonidia, in 
their preliminary state, of normal form, size, and arrangement ; 
and in this respect also there was conformity between the 
narrow part and the enveloping hyphoidal tubes of the coated 
filaments. 
It follows that one and the same cell would have been the 
theoretical alga on the widened and gonidiophorous side, and 
the theoretical fungus on the other side, which remained 
narrow and contained microgonidia—which proves, in the most 
absolute manner, the falsity of the theory, as the same cell 
could not belong at once to two classes of plants. We have 
here neither fungus nor alga: the whole is lichen, and 
nothing but lichen; and the two kinds of tubes, so different at 
the first glance, are only different states of development of 
one and the same organ. ‘The very slender hyphoidal tubes 
are the primary part containing the microgonidia. ‘This pri- 
mary part may remain always in that state; or it may become 
enlarged and elongated, whilst its microgonidia, produced by 
free formation, will pass to the state of gonidia; and then the 
slender hyphoidal tubes will have become large gonidiopho- 
rous tubes. 
