114 : МЕ. Н. М. WARD ON THE STRUCTURE, DEVELOPMENT, 
filamentous Chroolepide, that Coleochete scutata has to its simpler allies, and that the 
so-called genera “ Phyllactidiwm,” “ Phycopeltis," and “ Mycoidea? will be found allied 
in other respects besides habit and mode of growth. 
CONCLUSION. 
In the foregoing essay I have attempted to place on record all the facts obtained with 
respect to the structure and development of a so-called “ Epiphyllous Lichen,” and to 
draw those inferences which seem to me warranted by the knowledge gained by the 
observations made during various periods extending over two years or so. 
I claim to have established beyond reasonable doubt, and on independent grounds, 
that the mature Lichen is acompound organism, consisting of an Alga which furnishes 
the “ gonidial" layer, and of a pyrenomycetous Fungus, which invests the Algal thallus, 
and obtains its chief nourishment from the starch «с. contained in the cells of the latter. 
The value of the investigation as a critical test of the modern theory of Schwendener 
and De Bary * respecting the nature of Lichens generally, may be regarded variously 
according to the views held by different readers; but it appears incontestable that the 
following statements are true so far as the organisms here examined are concerned. 
An Alga, allied in important respects to Chroolepus, flourishes on the leaves of 
Michelia «с., and is undoubtedly an autonomous form. Its existence may be wholly 
independent, and its processes of vegetative and reproductive life carried on from one 
generation to another; or it may become the slave and, finally, the prey of a Fungus- 
mycelium, in the meshes of which it lives for some time. The fact that the exact 
relation of both Alga and Fungus to the substratum and to one another can be followed 
in detail by cultivations and sections through the whole, enables one to follow the 
building-up (so to speak) of the final structure, the “ Lichen,” without a shadow of 
doubt. 
But it is conceivable that objection may be made, to the following effect:—It is 
admittedly proved that the body which results consists of an Algal thallus enslaved and 
preyed upon by a parasitic Fungus; but it is not proved that the final structure is a 
Lichen in the proper sense of the term. Such argument has been used with respect to 
СоПетасеге &c. One can only leave those who hold such views to extricate them- 
selves from the difficulties into which such modes of thought unavoidably lead them. 
It is undeniable that a lichenologist would accept and classify the structure I have 
described as a “Lichen,” if attention were only paid to its anatomy T. It is worse 
than useless, therefore, to argue that because the “ hyphal” and **gonidial" elements 
are capable of separate existence as autonomous forms it is not a Lichen. This being 
* Cf. Schwendener in Niigeli’s Beiträge zur wiss. Bot. Heft ii., iii, iv., and De Bary, Morph. а. Phys. d. Pilze, 
Flechten, «с; also summary of the whole question in Quart. Journ. Mier. Sci. vols. xiii. and xiv. Mr. Vines gives 
an excellent summary of more recent details in Quart. Journ. Мег. Sci. April 1878; and the now copious literature 
is quoted in the three papers last named. 
+ Dr. Nylander and the Rev, J. M. Crombie have since done this. These authorities name the Lichen Strigula 
complanata, Fée, with var. stellata (the branched form). 
