The genus Oncidium has, perhaps, more examples of a startling combination in hues than any other—­but one must speak thoughtfully and cautiously upon such points.

I have not to deal with culture, but one hint may be given.  Gardeners who have a miscellaneous collection to look after, often set themselves against an experiment in orchid-growing because these plants suffer terribly from green-fly and other pests, and will not bear “smoking.”  To keep them clean and healthy by washing demands labour for which they have no time.  This is a very reasonable objection.  But though the smoke of tobacco is actual ruination, no plant whatever suffers from the steam thereof.  An ingenious Frenchman has invented and patented in England lately a machine called the Thanatophore, which I confidently recommend.  It can be obtained from Messrs. B.S.  Williams, of Upper Holloway.  The Thanatophore destroys every insect within reach of its vapour, excepting, curiously enough, scaly-bug, which, however, does not persecute cool orchids much.  The machine may be obtained in different sizes through any good ironmonger.

To sum up:  these plants ask nothing in return for the measureless enjoyment they give but light, shade from the summer sun, protection from the winter frost, moisture—­and brains.

* * * * *

I am allowed to print a letter which bears upon several points to which I have alluded.  It is not cheerful reading for the enthusiast.  He will be apt to cry, “Would that the difficulties and perils were infinitely graver—­so grave that the collecting grounds might have a rest for twenty years!”

January 19th, 1893.

DEAR SIR,

I have received your two letters asking for Cattleya Lawrenceana, Pancratium Guianense, and Catasetum pileatum.  Kindly excuse my answering your letters only to-day.  But I have been away in the interior, and on my return was sick, besides other business taking up my time; I was unable to write until to-day.  Now let me give you some information concerning orchid-collecting in this colony.  Six or seven years ago, just when the gold industry was starting, very few people ever ventured in the far interior.  Boats, river-hands, and Indians could be hired at ridiculously low prices, and travelling and bartering paid; wages for Indians being about a shilling per day, and all found; the same for river-hands.  Captains and boatswains to pilot the boat through the rapids up and down for sixty-four cents a day.  To-day you have got to pay sixty-four to eighty cents per day for Indians and river-hands.  Captains and boatswains, $2 the former, and $1:50 the latter per day, and then you often cannot get them.  Boat-hire used to be $8 to $10 for a big boat for three to four months; to-day $5, $6, and $7 per day, and all through the rapid development of the gold industry.  As you can calculate twenty-five days’ river travel to get within reach of the Savannah lands,