— 8 3 — 
The view that the lower Algae, which vegetate where Lichens are found, are 
Lichen gonidia escaped from the thallus, originated with Wallroth, and was of- 
ten expressed after him. There thus came to be two classes of followers: those 
who believed as Schwendener, and those who believed as Famintzin. 
Up to this time, the experimental formation of a Lichen from its two com- 
ponents had not been accomplished, and, until this had been done, the question, 
of course, could not be considered settled. This was left to Stahl. Stahl’s ex- 
periments, however, were not the first ones having this object in view. Already, 
in 1871, M. Reese had made the attempt, and he actually succeeded informing 
a thallus, but he was not able to bring it to the formation of fruit and spores. In 
the same year Bornet repeated Reese’s attempt, but with no better success. 
Treub, 1873, next tried, and again the results were no better than those of his 
predecessors. “This is, of course, what is to be expected,” said those opposed 
to Schwendener. Hear what Crombie, England’s great systematist, had to say 
upon the above experiments: “All these experiments, however, met with but 
a very limited amount of success, just as in the case of spore-culture by itself 
without any added ‘algals.’ Even where the spores successfully germinated 
and produced hyphae, all that could be affirmed was that these formed with the 
Algae a structure resembling in some degree the more or less rudimentary thallus 
of a Lichen. But it is to be observed with respect to these synthetical cultures, 
and all other experiments of a similar kind, that even were the results more pro- 
nounced than they have been, they would prove absolutely nothing as to the 
truth of the hypothesis. The Lichen-spore must, from its very nature, produce 
Lichen-hyphae, whether with or without the addition of algals or pseddo-algals; 
though what the fate of true added Algae in the subsequent evolution of the 
thallus might be, the experiments in Symbiosis do not show.” 10 
Crombie, like Nylander, never believed otherwise, than that Lichens formed 
a distinct class of plants. In the article, from which the above is quoted, page 
281, he says: “From all these various considerations and illustrations, to which 
others, though of minor importance, might easily be added, it is clear that the 
Algo-lichen hypothesis rests upon no solid basis whatever, but simply and solely 
upon imagination, and that it is merely a plausible attempt to explain certain 
phenomena which its author and adherents supposed to be otherwise inexplicable. 
Notwithstanding the laboured arguments by which it has been sought to deprive 
them of their autonomy and intrude them amongst the Ascomycetes, Lichens 
still remain a distinct class of plants, intermediate between the Algae and the 
Fungi, Lichens therefore are Lichens and nothing else — neither 
Fungi nor Algae, nor any intermixture of these; but everywhere and constantly 
preserving their own distinct type, and distinguished by many important char- 
acters peculiar to themselves.” 
It was in 1877 that Stahl succeeded in effecting the synthesis of three differ- 
ent species of Lichens. He did this by allowing the spores of the Lichens to ger- 
10 Rev. J. M. Crombie. On the Algo-Lichen Hypothesis, Linn. Journ. -Botany, Vol. XXI, 
pag 266. 
