THE ORCHID REVIEW. 399 
little ventilation goes along way. Others are low, the circulation being 
naturally sluggish. Some have air spaces between the laps, whilst some are 
so well and tightly built so as to entirely exclude all air unless the ventilators 
are open. For the latter I would strongly advise that the ventilators be 
always more or less open, even though it may only be a chink both top and 
bottom. 
Not only should the airing be carefully attended to and the atmosphere 
kept drier generally, but much less water is now required at the roots. Do 
not, however, let anything remain dry for long periods just at present, or 
they will be quite unable to plump up and mature. Later on, in mid- 
winter only, is when water may be withheld for weeks at a stretch. Cool 
Orchids will still require very little fire heat this month ; a few hours during 
the nights should they be exceptionally cold is all that is necessary. The 
Warm and Intermediate kinds will of course require more, but do not 
maintain it quite continuously just yet if avoidable, for fire heat, it should be 
borne in mind, is a necessary evil. Never do Orchids do 30 well as when it 
can be done without. Many days will doubtless yet occur when the hot 
water pipes may be cold, but as for the nights, a little warmth more or less 
is now indispensable. 
With the exception of a very few species, the Dendrobiums have now 
quite completed their new pseudobulbs, and should be given cool, airy 
quarters, where they canripen and set their flower buds. The New Guinea 
kinds, as D. Phalznopsis, D. bigibbum, D. superbiens, D. macrophyllum, 
D. atroviolaceum, and D. Johnsone, together with D. formosum, and a 
few other similar heat-loving kinds, should never be rested in a temperature 
lower than the Intermediate house. But for all others a Cool house 
temperature is the best. Those that will take the greatest amount of cold 
if dry at the root are the D. thyrsiflorum and densiflorum group, and D- 
Wardianum. For the latter a very cold winter treatment is essential until 
February, or they will not be long lived. 
-Miltonias of the spectabilis group having now passed out of flower 
should, of course, have but little water applied to their roots, and be allowed 
to enjoy a good long rest. I find the warmth of the East Indian house to- 
agree with these kinds the best. M. vexillaria and its varieties, together 
with M, Phalzenopsis, are actively growing, and should be in a light, airy 
Position in the Cattleya house, where the roots should be kept moist only, 
avoiding too much water. Those of the M. Clowesii and candida types are 
also best accommodated in the Cattleya house, keeping them dry ved moist 
according to their stage of growth. Some are now producing their flower 
Spikes, which of course must not be starved for want of water. 
The Mexican Lzelias will now be producing their flower spikes freely, 
and must still be aided well by fairly large supplies of water, indeed, they 
