— 81 — 
him of the truth of the surmise, and in the same year, September, 1867, he pres- 
ented his now famous talk “On true nature of Lichens” before the Swiss Natur- 
alists’ Club at Rheinfelden. The same was communicated by letter to DeBary, 
and was published by Von Mohl in 1868 in the Botanische Zeitung. Here he 
expresses the opinion that the gonidia of various Lichens correspond to certain 
low forms of Algae. His conclusions at that time, may be summarized as fol- 
lows: 8 (1). There is no direct proof of any genetic relationship between the goni- 
dia and the hyphal elements. (2) The cell-walls of the gonidia have a different 
chemical behavior from the membranes of the hyphae; the former react simi- 
larly to those of Algae; the latter similarly to those o f Fungf. (3) As to struc- 
ture and development, the various forms of gonidia correspond to different forms 
of Algae. The resemblance is so close that in many cases a given isolated goni- 
dium cannot be distinguished from the corresponding Alga. 
The next year 1869, he published his “Die Algentypen der Flechtengonidien”. 
Here is what he says in his preface: “According to my investigations, these 
growths are not simple plants, not individuals in the ordinary sense of the word, 
they are more likely colonies, composed of hundreds and thousands of indivi- 
duals. Of them, however, one only is in control, whilst the others, forever im- 
prisoned, provide for themselves and their master, nourishment. 
“This master is a fungus, of the class Ascomycetes, a parasite, accustomed 
to live upon the work of others, its slaves are green Algae, which it has gathered 
around itself, at any rate, holds on to and forces into service. It invests them 
as a spider her prey, with a fine meshed web, which gradually is converted into 
an impregnable integument, but, whilst the spider sucks out her prey and throws 
it aside when dead, the Fungus stimulates the Algae, found in its net, to more 
lively activity, in fact, causes them to grow larger and causes thereby a luxur- 
iant growth and the thrifty appearance of the whole colony.” 
About the same time that Schwendener was making his investigations, two 
other botanists, Famintzin and Baranetsky were also working upon the develop 
ment of the gonidia. These two investigators had succeeded in developing the 
gonidia of three different Lichens apart from their thallus, ( Xanthoria parietina, 
Evernia furfur acea, and a Cladonia ). They made the interesting discovery that 
many of these gonidia produced zoospores, whilst others dividing themselves in 
various ways, formed masses of cells which separated and rounded themselves; 
in fact, they concluded that the gonidia, thus capable of living apart, were iden- 
tical with the Alga Cystococcus. They concluded from this that the forming of 
zoospores was not only peculiar to Algae and Fungi, but also to Lichens; further- 
more, that Cystococcus was now no longer to be looked upon as an independent 
Alga, but one of the forms in the evolution of a Lichen, and that many more such 
forms would likely be discovered later and withdrawn from the Algae. They 
believed, therefore, that many of the unicellular Algae were merely free Lichen 
gonidia. 
8 Schneider. A Text book of General Lichenology, page 24. 
