[Illustration:  ONCIDIUM MACRANTHUM Reduced to One Sixth]

Nature forestalled the dreams of aesthetic colourists when she designed Oncidium macranthum.  Thus, and not otherwise, would the thoughtful of them arrange a “harmony” in gold and bronze; but Nature, with characteristic indifference to the fancies of mankind, hid her chef-d’oeuvre in the wilds of Ecuador.  Hardly less striking, however, though perhaps less beautiful, are its sisters of the “small-lipped” species—­Onc. serratum, O. superbiens, and O. sculptum.  This last is rarely seen.  As with others of its class, the spike grows very long, twelve feet perhaps, if it were allowed to stretch.  The flowers are small comparatively, clear bronze-brown, highly polished, so closely and daintily frilled round the edges that a fairy goffering-iron could not give more regular effects, and outlined by a narrow band of gold. Onc. serratum has a much larger bloom, but less compact, rather fly-away indeed, its sepals widening gracefully from a narrow neck.  Excessively curious is the disposition of the petals, which close their tips to form a circle of brown and gold around the column.  The purpose of this extraordinary arrangement—­unique among orchids, I believe—­will be discovered one day, for purpose there is, no doubt; to judge by analogy, it may be supposed that the insect upon which Onc. serratum depends for fertilization likes to stand upon this ring while thrusting its proboscis into the nectary.  The fourth of these fine species, Onc. superbiens, ranks among the grandest of flowers—­knowing its own value, it rarely consents to “oblige;” the dusky green sepals are margined with yellow, petals white, clouded with pale purple, lip very small, of course, purple, surmounted by a great golden crest.

Most strange and curious is Onc. fuscatum, of which the shape defies description.  Seen from the back, it shows a floriated cross of equal limbs; but in front the nethermost is hidden by a spreading lip, very large proportionately.  The prevailing tint is a dun-purple, but each arm has a broad white tip.  Dun-purple, also, is the centre of the labellum, edged with a distinct band of lighter hue, which again, towards the margin, becomes white.  These changes of tone are not gradual, but as clear as a brush could make them.  Botanists must long to dissect this extraordinary flower, but the opportunity seldom occurs.  It is desperately puzzling to understand how nature has packed away the component parts of its inflorescence, so as to resolve them into four narrow arms and a labellum.  But the colouring of this plant is not always dull.  In the small Botanic Garden at Florence, by Santa Maria Maggiore, I remarked with astonishment an Onc. fuscatum, of which the lip was scarlet-crimson and the other tints bright to match.  That collection is admirably grown, but orchids are still scarce in Italy.  The Society did not know what a prize it had secured by chance.