ON THE GERMINATION OF ORCHIDS. 295 
year, at two different periods, from the roots of the same clump of 
Odontoglossum, have acted very differently on the germination of the 
same variety of seeds of this family. Hveryone knows that the bacteria 
which produce a great many animal diseases are often more or less 
injurious, according to the conditions of their collection and of their 
culture. Similarly, the fungi of orchids are capable of varying degrees 
of “virulence’’; they are more or less active, according to their origin 
and their age. 
I have recently discovered that it is possible to restore a sufficient 
activity to the fungi when their powers have been impaired. It is 
enough to let them live for some time in the embryo of an orchid, the 
seed of which it is desired. to germinate. The fungus can live for some 
time inside the embryo, although this does not develop, and when it is 
taken out after, say, two months, it can exhibit sufficient activity to make 
the seeds germinate which formerly appeared to resist its action. By 
using this process of passage through the embryo, I have been able to 
restore to my oldest cultures of fungi all their original activity which they 
had lost. 
Amateur orchid-growers have often told me that they attach great 
importance to the discovery of sure and practical methods of securing the 
germination of the seeds of orchids. Some of them, having knowledge 
of my researches, have begged some of the fungi to sow with their seeds ; 
they have sometimes secured good results, but often they have met 
with no success. This is due to many causes, but chiefly to the fact that 
the fungi were to be used in the germination of, species of orchids from 
which I had never made cultures. The fungi supplied had, moreover, not 
the requisite virulence. The cultures from which they were taken were 
more or less old, and had been prepared according to the requirements 
of my experiments, and not for the definite purpose for which my 
correspondents required them. 
So as always to be able to produce a fungus suitable for the ger- 
mination of orchids of a certain species, cultures of the seeds of that 
species should be made every year in the laboratory, in order to maintain 
and even to increase the strength of the fungus in question, thus keeping 
it alive without interruption in the embryo, whence it may be taken as 
required. 
A laboratory attached to a greenhouse sufficiently well supplied, and 
specially reserved for this horticultural work, would without doubt be 
able at all times to furnish horticulturists with the fungi suitable for 
the germination of their seeds, but it must be borne in mind that this 
would necessitate continuous and minute work. The reward would be the 
possibility of obtaining more easily the germination of the seeds of 
hybrids. 
In taking account of the important part played by fungi in the 
germination of orchids, one would be able to hope for novel results. 
In the course of experiments still incomplete, I have proved the 
possibility of raising the same orchid with the fungi of different species. 
For example, seeds of Cattleya have germinated with the fungus of 
