* 
- . 5 
The flowers are attractive in shape and colouring but the inflorescence is 
unpleasingly long and floppy, with the flowers spaced too far apart. Further 
crossings are necessary, and are being made, to improve the shape of the 
inflorescence. 
Some 350 pollinations were made during the year, not all of which, of 
course, yield seed. Numerous crosses involving various kinds of Aranda 
(Arachnis-Vanda hybrids) were attempted, mostly without success. Large pods 
may result, but they are usually quite devoid of seed. 
The introduction of a number of fine hybrids from Honolulu has enabled 
a number of crosses to be made between them and locally produced hybrids. 
The beds in which various Vandas, Arachnis, Arandas, Arantheras, etc. 
are grown have been kept supplied with half-rotted compost well heaped up 
round the bases of the plants. This takes a great deal of compost, but the 
plants benefit. 
A number of the less hardy strap-leaved Vandas, some Cattleyas, Den- 
drobiums, etc., were transferred to hanging baskets filled mainly with large 
pieces of charcoal and given light shade. There is no doubt that the plants 
respond to this treatment, and a plant of Euanthe Sanderiana, always delicate 
in Singapore, is growing well under these conditions. 
The number of flasks of seedling orchid hybrids on the racks in the 
Laboratory totalled 1,200 at the end of the year. This represents an enormous 
number of seedlings. 
Some changes have been made in the culture medium and certain experi¬ 
ments have been initiated by Mr. J. L. Pestana to ascertain whether the growth 
rate and vigor of the seedlings can be increased. The acidity of the medium 
has been increased to pH 5 from approximately pH 6.2 and the acid used 
has been changed to citric acid in preference to hydrochloric acid, which has 
been used hitherto. Better germination has been observed, and there has been 
an appreciable increase in the rate of growth; at the same time the seedlings 
appear to be healthier and sturdier. 
The control of infection of flasks by moulds is extremely important. 
Considerable improvement in this respect has been made by impregnating the 
cotton wool plugs with 0.1 per cent mercuric chloride and 0.1 per cent picric 
acid dissolved in absolute alcohol. Previously, the plugs were disinfected with 
a solution of copper sulphate, but . this tends to cause shrinkage of the plugs 
and opens gaps between them and the necks of the flasks which admit fungus 
spores. The new technique has resulted in almost complete control. 
When seedlings are removed from their flasks and put out into pans in 
finely broken brick, their growth is checked. They are watered with tap water, 
which is considerably more alkaline than the medium in the flasks, and to 
ascertain whether this check in growth is due to the difference in pH between 
conditions in the flask and conditions outside, the water used for watering the 
seedlings is now acidified to pH 5 and careful watch is being kept for results. 
The succulent collection has been increased by the introduction of seed 
and plants from abroad and has been kept in good order. Some plants of 
Conophytum, Lithops, Faucaria, Pleiospilos, etc., of the Mesembryanthemum 
Family, native in the driest parts of South Africa, have grown remarkably 
well. One Conophytum has flowered. 
PLANT SALES 
Revenue from plant sales was $18,862, of which $14,500 resulted from 
the sale of surplus orchid plants and seedlings. 22,900 plants were sold, of 
which 2,900 were orchids. 
