June, 1918.) THE ORCHID REVIEW. 135 
plants require abundance of water whilst making their growth ; during this 
later stage they must not be allowed to shrivel for the want of it 
afterwards they require a decided resting period. The compost should be 
placed in the receptacles moderately firmly, and the plants must be shaded 
from strong sunshine during the growing period. Many of the species are 
of a rambling nature, and some pains must be taken to keep them in a 
compact form. 
GENERAL REMARKS.—After a period of bright sunshine, such as we have 
recently enjoyed, thrip, and other insect pests are often troublesome, so that 
it is essential to keep a sharp look out, and exterminate them by the usual 
methods should they put in an appearance. It is difficult during these 
strenuous times to attend to everything, but this is a matter that will not 
wait, and the plants must be maintained in health until the return of 
normal times. 
Ae 
Root-Func1 or ORcHIDs.—With respect to the notes at pp. 55, 96, on 
the seedling Phalznopsis Sanderiana X rosea germinating in an aseptic 
tube, M. Fernand Denis, Balaruc-les-Bains, sends us an interesting extract 
from a posthumous work by the late M. Noel Bernard, entitled 
“ L’ Evolution des Plantes,” completed by his wife. At page 286 occurs a 
note on the germination of Orchids, of which the following is a summarised 
translation. ‘Germination by the action of concentrated solutions is very 
slow but very regular; the young embryos have the ordinary appearance, 
and the seedlings are sufficiently developed to live in the houses after being 
transplanted. Under the conditions of my experience with the technique of 
Pasteur’s culture, it is better and easier to germinate certain Orchids by the 
use of concentrated solutions than to have recourse to the fungus 
Rhizoctonia, of which it is often difficult to procure races sufficiently active. 
We may therefore conclude that although the fungi have their special 
function, it is possible to substitute for this symbiosis diverse conditions 
which are easily realisable, and which are followed by similar results.” 
M. Denis concludes that he had good reason for believing that his friend, 
M. Noel Bernard, during the later years of his life, realised that his former 
views were too exclusive, and the extract also affords a possible clue to the 
reason why the seedling Phalaenopsis Sanderiana X rosea was successfully 
germinated in an aseptic tube, the role of the fungi being secured by other 
Means. It is all a question of nutrition. The highly-specialised seeds of 
Orchids seem to contain an insufficient store of nutriment to carry them 
Over the initial stages of germination, and have contracted a habit of relying 
on the assistance of the root-fungi. The possibility of supplying the 
deficiency by the concentrated solutions mentioned affords interesting 
Possibilities for the future ——R.A.R. 
