THE EXISTENCE of a mutually beneficial symbbiosis
between orchids and certain filamentous fungi
has been inferred for a number of years. Two principal
arguments have been offered in support of this
symbiotic view, both of them dealing with the relation
of the fungi to the germination of the orchid
seeds. The main thesis was advanced by Bernard in
1904 and subsequently supported by Burgeff (1909,
1911, 1936), Costantin (1917), and Ramsbottom
(1922, 1927). They maintained that orchid seeds
would not germinate without the aid of endophytic
fungi found in the roots of the orchids. The second
argument dealt with an alleged specific relationship
between the orchid and the fungus species
and was also advanced by Bernard (1909), who
claimed that different orchid plants of the same
species or the same genus would always harbor the
same species of fungus. This view was held as late
as 1927, when Ramsbottom stated that "The same
fungus is always present in Cattleya roots and is
distinguishable in culture, even with the naked eye,
from a culture of the fungus from Odontoglossum.