THE ORCHID REVIEW. 221 
heavily during bright weather, removing the same about five or six o'clock. 
Keep all the inmates well supplied with moisture, fumigate on the 
slightest traces of yellow thrip, or yellow or green fly. For the House 
proper, continue the management recommended in_ last month’s 
Calendar. 
FLOWERING OF MALAYAN ORCHIDS. 
An interesting paper on the Flora of Singapore, by Mr. H. N. Ridley, 
Curator of the Singapore Botanic Garden, has recently appeared in the 
Journal of the Asiatic Society, Straits Settlement branch, from which we 
make some extracts as to the period of flowering of the Orchids of this 
district :— 
Very few plants have a definite flowering month. A large number 
flower more or less regularly throughout the year. Others flower at regular 
periods three or four times a year, almost every plant of a given kind 
flowering simultaneously in the district. This is best known in the case of 
the Pigeon Orchid, Dendrobium crumenatum. In this plant the flowers 
are produced at periods of a little over a month, or two months. The 
exact day differs in different parts of the peninsula, but in each district they 
all appear on the same day, and it is remarkable that plants brought to | 
Singapore, even from as far north as Siam, open their flowers on the day for 
Singapore, and not on that for Siam. It is not rare, however, to find certain 
plants of Pigeon Orchid which do not flower on the regular day, but have a 
distinct day, which they appear to keep with equal regularity. A curious 
fact is that another species of Dendrobium (D. criniferum) invariably flowers 
in Singapore on the day preceding that of D. crumenatum, whenever that 
happens to be. It might be thought that the weather in the district in 
which the plant was growing was the influencing agent, but this appears to 
have but little effect on the Orchids. On one occasion (Dec, 5th, 1893) 
the Pigeon Orchids developed their flowers so far that they were obviously 
_ ready to open them on that day, but an extraordinarily heavy rain retarded 
them, and the flowers opened the next day, but, except in cases like this, the 
weather previous to the flowering does not seem to make any difference to 
the date of flowering. . . - Itcan easily be understood that it is very 
important to a plant that all should open on the same day, in order that 
they may be cross-fertilised by the insects that visit them, and this is 
especially the case in plants in which the flowers last but a single day, as 
in the case of the Pigeon Orchid, but it is difficult to see how this is brought 
about. Some few plants have a regular flowering season, such as Calanthe 
-__curligoides, in September, and Grammatophyllum, July and August.” 
