14.3 “Untersuchungen über den Flechtenthallus II. Laubund Gallertflechten” by Simon Schwendener, 1868
Simon Schwendener (1868) included as the addendum of this publication a conclusion that, based upon his detailed observations, at least some lichens are composed
of algae and fungi. By my translation, his statement was “The decision as to whether
and to what extent the assumption of a thallus formation due to the growth of
parasitic fungi with algae is justified remains largely open to investigation. However,
since the possibility of such a process and in some cases even the likelihood of it can
no longer be disputed, the question arises whether or not all lichens may arise in the
same way: whether the gonidia should be continuously [considered as a] typical
algae and the colorless hyphae are to be regarded as mushroom hyphae [fungal
hyphae], which [for the purpose of] the construction refer [to a required food for the
Thallus]. As things stand at present, there are many things to be said for and against
such a view, and the judgment of the individual will vary depending on the weight he
attaches to the facts in question.” He included among his named algae Cystococcus
humicola and Cystococcus Nägeli both of which we now consider to be
Chlorococcum humicola, along with three genera which we now consider to be
cyanobacteria (phylum Cyanobacteria) and those were Chroococcus, Gloeocapsa,
and Nostoc.
14.4 “Über die biologischen Verkältnisse des Thallus
einiger Krustflechten” by Bernhard Frank, 1877
Albert Bernhard Frank is credited with initially proposing in this 1877 publication
the term ‘symbiotism’ (Frank 1877). Frank had been studying lichens, which consist
of a fungal thallus that we now understand typically to be colonized by either a
cyanobacteria or an alga, and he said that together these two biological elements lead
a double life. I included an image of one particular lichen, Letharia vulpina also
known as the wolf lichen, as part of the photomontage image “Volvox reimagined”
which I created and appears on the book cover for this series. Letharia vulpina is
described as having a fruticose growth form, growing like a multiple-branched tuft
or leafless mini-shrub.
Frank noted that there seemed to be a useful connection between what we now
know as the lichen mycobiont, which typically is an ascomycete (member of the
phylum Ascomycota) although some lichens do instead have a basidiomycete
(member of the phylum Basidiomycota) as their mycobiont, and the lichens Gonidia.
That part of a lichen not involved in reproduction is termed the thallus and composed
of fungal hyphae. Gonidia is a term used to describe parts of the lichen which then
still were considered to be ‘brood cells’ or reproductive organs of the lichen. The
sexual reproduction structures of lichens were termed apothecia and contained the
gonidia. Frank thought that it was wrong to consider the Gonidia as being analogous
14 Discovering the Symbiotic Nature of Microbial Life: Summarizing Milestone. . .
215
Simon Schwendener (1868) included as the addendum of this publication a conclusion that, based upon his detailed observations, at least some lichens are composed
of algae and fungi. By my translation, his statement was “The decision as to whether
and to what extent the assumption of a thallus formation due to the growth of
parasitic fungi with algae is justified remains largely open to investigation. However,
since the possibility of such a process and in some cases even the likelihood of it can
no longer be disputed, the question arises whether or not all lichens may arise in the
same way: whether the gonidia should be continuously [considered as a] typical
algae and the colorless hyphae are to be regarded as mushroom hyphae [fungal
hyphae], which [for the purpose of] the construction refer [to a required food for the
Thallus]. As things stand at present, there are many things to be said for and against
such a view, and the judgment of the individual will vary depending on the weight he
attaches to the facts in question.” He included among his named algae Cystococcus
humicola and Cystococcus Nägeli both of which we now consider to be
Chlorococcum humicola, along with three genera which we now consider to be
cyanobacteria (phylum Cyanobacteria) and those were Chroococcus, Gloeocapsa,
and Nostoc.
14.4 “Über die biologischen Verkältnisse des Thallus
einiger Krustflechten” by Bernhard Frank, 1877
Albert Bernhard Frank is credited with initially proposing in this 1877 publication
the term ‘symbiotism’ (Frank 1877). Frank had been studying lichens, which consist
of a fungal thallus that we now understand typically to be colonized by either a
cyanobacteria or an alga, and he said that together these two biological elements lead
a double life. I included an image of one particular lichen, Letharia vulpina also
known as the wolf lichen, as part of the photomontage image “Volvox reimagined”
which I created and appears on the book cover for this series. Letharia vulpina is
described as having a fruticose growth form, growing like a multiple-branched tuft
or leafless mini-shrub.
Frank noted that there seemed to be a useful connection between what we now
know as the lichen mycobiont, which typically is an ascomycete (member of the
phylum Ascomycota) although some lichens do instead have a basidiomycete
(member of the phylum Basidiomycota) as their mycobiont, and the lichens Gonidia.
That part of a lichen not involved in reproduction is termed the thallus and composed
of fungal hyphae. Gonidia is a term used to describe parts of the lichen which then
still were considered to be ‘brood cells’ or reproductive organs of the lichen. The
sexual reproduction structures of lichens were termed apothecia and contained the
gonidia. Frank thought that it was wrong to consider the Gonidia as being analogous
14 Discovering the Symbiotic Nature of Microbial Life: Summarizing Milestone. . .
215