THE ORCHID REVIEW. 
[October, 1921. 
the house. The longer nights and cooler atmosphere may necessitate the 
rise of a little fire-heat in the cooler division's, it being better to have some 
warmth in the pipes, with the ventilators open a little, than to close the house 
without heat, as a saturated atmosphere, accompanied by a low tempera¬ 
ture, is most injurious to all Orchids. 
Dendrobium. —The deciduous section of this genus, many kinds of 
which produce their flowers early in winter, are rapidly completing their 
season’s growth. When the apical leaves of the pseudobulbs are fully 
developed, the plants need much'drier conditions, not sufficient to cause 
shrivelling, but less water at the roots than at their growing season. It is 
'essential that these plants be accommodated where they can be afforded 
jplenty of fresh air, and where they can obtain the maximum amount of 
sunshine to thoroughly harden the growths. When the latter is completed 
the plants should be rested in a well-ventilated house, in which an inter¬ 
mediate temperature is maintained. Backward plants should be given every 
encouragement to complete their season’s growth before the days get 
shorter. These remarks also apply to the evergreen species that flower in 
the spring. The species D. Dalhousieanum, D. moschatum and D. fim- 
briatum are always late in finishing their growths, and the plants should be 
afforded liberal treatment until the terminal leaf is visible. D. Brymer- 
ianum is also a late growing kind. These evergreen species should be 
grown in the warmest division at all seasons, but during the winter, while 
the plants are resting, infrequent waterings will suffice to keep the pseudo¬ 
bulbs plump and the roots healthy. Plants of D. Phalamopsis Schroder- 
ianum have their flower-spikes well advanced, if not already in bloom. 
Foggy weather of late autumn has a pernicious effect on these attractive 
flowers, and it is an advantage, especially in the vicinity of large towns, to 
have the plants in bloom early. For so long as the plants are carrying 
flower spikes, a moderate amount of water should be afforded the roots, but 
after these have been removed, sufficient moisture only is required to keep 
the pseudobulbs from shrivelling. During the plant’s inactive period, an 
intermediate temperature is best for them. D. formosum blooms at various 
times, but usually in late summer and autumn. The plants grow well in 
company with the last-named species, requiring an almost unshaded posi¬ 
tion, where there is plenty of heat and moisture. This species does not 
require large supplies of water, even during the growing season, and in 
winter very little moisture will suffice to keep the pseudobulbs from 
shrivelling. D. infundibulum belongs to the same section as the last- 
named species, and the cultural treatment is similar, except that it grows 
best in a cool-intermediate temperature. 
Vanda cojrulea.— This Orchid, now to be seen in flower, produces 
much better coloured blooms in districts where the atmosphere is pure than 
