The mention of the illustrious traveller's name reminds me of the obligations under which he laid me when I first visited Berlin, in the spring of 1836; for, young as I was, he deigned to pour into my delighted ears all the stores of Orchid-lore collected during his memorable wanderings among the Andes of New Grenada and Peru. Here, he said, the greatest store of beauteous Orchids was to be found, and we are now beginning to realize the truth of his remark.

Cool Orchids from the interior of South America, have either to be carried across the Andes, where the intense cold of the passes is often fatal to them, or to be conveyed by a tedious voyage down the great rivers, where the heat is greater than their constitution—often delicate—can endure. In this way whole importations have been lost, including, I am sorry to say, one or two cargoes of the exquisite Odontoglossum Warczewitzii (figured in Reichenbach's "Xenia") which still unhappily remains a desideratum.

As most of the Odontoglossa require to be treated in the same way, I transcribe, from the 'Guide to Cool-Orchid Growing' (Reeve, 1864), the following instructions for the culture of the genus:—"They will all succeed perfectly in a low lean-to house facing the north, the mean temperature of which need not exceed 60°. They should stand on a shelf of slate or stone, near the glass, but should always be protected from the direct rays of the sun. Constant humidity should be maintained by damping the shelves and floors, but the plants themselves will only require water in moderation, and what is given to them should pass away freely, for if it stagnates, or if the compost in which they grow becomes sodden, the roots will immediately decay. A gentle evaporation is greatly assisted by placing layers of moss—to be kept damp of course—on the shelves whereon the plants stand. Odontoglossa cannot endure wooden blocks, but will thrive in a compost of which one-half consists of small broken potsherds, the remainder being a mixture of shredded sphagnum (dusted with fine sand) and fibrous peat. About one-third of the entire depth of the pots may be filled with this mixture, the other two-thirds containing nothing but large pieces of broken pots, so as to admit as much air as possible to the roots. The pots in which the plants are grown should stand on other pots (inverted) placed in saucers of water, in order to secure humidity and protect them from wood-lice. Nearly all the species flower during the winter or spring months, a circumstance that greatly enhances their value. Many, e. g. O. pulchellum, are deliciously fragrant, and the flowers of nearly all the species remain in perfection for weeks, whether left on the plants or cut for bouquets. In so vast a genus we shall, no doubt, meet with many idiosyncrasies, but nine-tenths of the species will flourish under the treatment indicated above, and which may be regarded as suitable to the majority of cool Orchids. Most Odontoglossa are, like the Masdevallias, very impatient of the knife, and cannot therefore be rapidly multiplied. They have also a peculiar aversion to fumigation by tobacco, which causes their leaves to fall off."

The idea that Cuitlauzina pendula might possibly be identical with Odontoglossum citrosmum had more than once occurred to myself, but Lexarza's character of the flower-scape,—which he described as "bracteis destitutus,"—had always proved an insuperable difficulty. It seems, however, that the scapes of the other Odontoglossa that he met with happened to be entirely clothed with large inflated bracts; our present plant therefore, in which they occur only at long intervals and are exceedingly minute, may in comparison be said to be almost "destitute" of them.

Mr. Skinner has lately received from Guatemala some magnificent specimens of O. grande, which are incorporated with masses of Fern and other shade-loving plants. Cultivators might make a good practical use of the well-known maxim "noscitur a sociis" in this case.

I copy Sir Robert's description of the locality in which these plants were found, in the hope that some collector may be induced to visit so interesting a region:—"The Diothonea was met with on the high mountain-chain between the sixty-fifth and sixty-sixth meridian and the fourth parallel of latitude, at an elevation of 6-7000 feet above the sea-level. The summits of those elevations are thickly covered with two species of Lichen, the white colour of which conveys the supposition that the ground is covered with snow. The thermometer stood frequently in the morning at 57° F., which, connected with the snow-white Lichens, powerfully reminded us of a winter landscape. Indeed, the stunted trees, with grey tortuous branches, would have assisted to make the picture complete, if numerous OrchidaceÆ, conjointly with green Mosses, had not clothed them. Indeed, it was the OrchidaceÆ alone that gave the vegetation a tropical aspect.... We discovered the Maxillaria near Mount Maravaca."—Lindl. Sert. Orch. sub t. xl.

I allude of course to those remarkable works of Dr. Lindley, the Orchidearum Genera et Species and the Folia Orchidacea (the latter of which he was not destined to complete), with which the science of Orchidology may be said to have arisen, and which will continue its text-books for all time to come.

It may be well, once for all, to state that in the case of species that have not been long imported, and which have therefore not had time to acquire their full strength, the number and arrangement of flowers in the figures is taken from native specimens where such are available. It sometimes happens that the "wild" standard is never reached in cultivation, but it is more frequently exceeded.