DECEMBER, 1906.] THE ORCHID REVIEW. 372 
Focs.—Fogs are a very real evil in London, and, although we have 
spells of good weather during the winter, we never pass the dull season 
without several visitations. I have seen it recommended to keep the 
plants on the dry side, and the temperatures lower than usual during spells. 
of fog, and I dare say this is all one can do, after shutting the houses up 
close. But one is frequently caught napping at night. I have gone to 
bed when the air was beautiful and clear, and found the houses full of fog 
in the morning. The effect that a London fog has on vegetation is well- 
known. Flowers wither up as if they had been held in an oven, buds are 
arrested and yellow off, and also tender foliage. To show these effects the 
fog does not require to be very dense, or of long duration. But while these 
happenings are apparent, how much is there done that is not apparent ? 
Plants with thick foliage, such as Cattleyas, may give no great and visible 
indication of mischief, such as turning yellow, but the damage must be 
there none the less, if more subtle. The sterilizing influences of the 
sulphurous gases contained in the fog—if able to turn the foliage of some 
plants yellow, and blast both flowers and buds—must play an enormous 
amount of unseen and unrecorded havoc. One fog a year is sufficient to 
stunt plants that are growing, and so stun those that are at rest that they 
have not that fierce impulse to start when their period of quickening 
arrives. There are fogs on sea and land, but these have nothing in common 
with the London fogs, excepting in moisture, and they are always quite 
harmless, and very frequently most beneficial to vegetation. Evergreen 
epiphytal Orchids are the plants to feel most—or give most evidence of— 
the debilitating effects of this destructive scourge, but, as I have no 
remedy to suggest, to enter further into the question will be waste of 
time. 
Cattleya Triane, C. Percivaliana, &c., may be showing their buds at 
the base of the sheaf, but how to treat these plants when in flower and bud 
was discussed at some length in the February Calendar. 
There are a good many winter flowering Orchids, and these should be 
placed where they can be seen to the best advantage, and also where they 
can receive the best possible light when developing their Hower spikes. 
Some of these are Cymbidium Tracyanum, Lycaste Skinneri, Zygopetalum 
Mackay, &c. 
Now that winter is nearly here, and seeing that I have been putting 
things nicely to rest for some time past—having, in fact, run myself aground 
as far as Calendarial matter is concerned—it is fortunate that I recollect 
the Editor once telling me that I might introduce seasonable hints from 
time to time. A few things suggest themselves to me which might make 
profitable reading, and which have the merit of being in season at all times, 
although, strictly speaking, my year’s Calendar ends here. 
