JuLy, 1906. | 
THE ORCHID REVIEW. 
FUNGUS CO-OPERATION IN ORCHID ROOTS. 
THE May number of the Orchid Review contains, under the title ‘“‘ Fungus 
Co-operation in Orchid roots,” 
researches on the germination 
of Orchids and, in particular, 
Odontoglossums (p. 154). I 
am pleased to send you a photo- 
graph showing the results of 
my experiments in this subject. 
The culture tubes represented 
in the photograph (fig. 24) are 
ordinary glass tubes, closed by 
a plug of cotton-wool and 
covered above this by a cap of 
tinfoil, so as to render impossible 
the entrance of moulds or other 
micro-organisms. These tubes 
have been sterilised by heat 
before making the cultures. 
The left-hand tube contains 
seeds of an Odontoglossum 
which had been sown aseptic- 
ally, without any other growth, 
on the inclined surface of the 
whitish nutritive jelly occupy- 
ing the lower part of the tube, 
and had remained for a period 
of four months. These seeds 
have simply turned green and 
swollen slightly, but they have 
not otherwise developed, and 
they are in the photograph only 
distinguishable as points on the 
wet surface of the jelly. 
The second tube contains a 
culture made in the same way 
with the seeds of the same 
plant, but which has_ been 
inoculated for two and a-half 
an 
article 
in 
which are 
discussed 
my 
months with a fungus found on the roots of Odontoglossums. The fungus 
has developed, forming on the surface of the nutritive jelly a delicate net- 
