1086 REPORT—1885. 
protoplasmic bodies are unchanged. On advancing nearer the pseudobulb the cell 
is often filled with the threads; nucleus, protoplasmic bodies, starch granules 
‘seem to have disappeared, and only the fungus with a small quantity of cell sap 
appears to be left. Such a section, however, when treated with suitable reagents, 
shows the nucleus among the anastomosing filaments of the fungus without loss of 
shape or of size. 
Often the cell-sap gathers into a lump in the centre of each cell, from the 
edges of which cell threads run in and surround the lump. 
By the application of a sugar solution the plasma is drawn off from the lump 
of mucilage which once more, after the removal of the solution, swells up as 
before. From this it is evident that the protoplasmic bodies are not destroyed by 
the fungus. 
The thickness of the cell-wall, too, plays no unimportant part in the distri- 
bution of the mycelia. Where the walls are thick the threads have greater 
difficulty in penetrating, and are not so numerous and strong as in roots where 
the cell walls are thinner and therefore more easily penetrated. 
Schultze’s solution colours the cell membrane a beautiful violet colour and 
makes the threads disappear. 
The growing thread appears with its apex at the middle of the cell wall, and 
where it has penetrated there is a slight swelling, both where it enters and where 
it emerges from the cell wall. The edge of the aperture where the threads have 
penetrated is quite smooth, so that it may be concluded that the membrane has 
been dissolved at the point of penetration. 
Entrance of Mycelia into Roots. 
In what way do the fungi first enter the aerial roots? I have examined plants 
recently imported in a shrivelled condition and have found no trace of fungi. 
Two years after importation still no trace; only when the plants have become 
established and comparatively vigorous in growth do the fungi seem to enter. 
That they penetrate the outer covering is evident from the following experiment. 
A plant of Platanthera bifolia was taken whose next year’s tubers were ripe and 
already contained mycelia. These tubers were placed under a bell jar along with 
tubers not yet containing any trace of fungi. In four or five days these latter 
were infected. In their outer cells a slightly branched mycelium was found. 
Again, does the orchid thrive better with or without the fungus? The evi- 
dence for and against is conflicting. I always noticed that the strongest, healthiest 
plants, those which produced the largest spikes of flowers, contained the most 
highly developed fungi. ; i 
It may be that we have here an instance of symbiosis; it may be that the 
fungus is imprisoned by the orchid, and made to gather nourishment for it, or 
afford nourishment to it, or the fungus may be a parasite pure and simple, 
It is a noteworthy fact that orchids brought to this country in a dry withered 
condition begin to grow most vigorously when the aerial roots are entered by the 
fungi. On the other hand, these roots are not entered until they have attained a 
certain vigour. Their vigour, therefore, may be the cause of the infection, not the 
effect of it. 
Lastly, the cultivation of these fungi has never yet resulted in the production 
of any fructification, so that no clue has as yet been obtained as to the genera or 
species of the fungus. 
I hope by the examination of a much greater variety of species of foreign 
orchids and of our native orchis yet to throw some little light on this subject. 
5. Notes on Experiments as to the Formation of Starch in Plants under the 
influence of the Electric Light. By H. Marswart Warp. 
