Masdevallias are so attractive to insects, by striking colour, as a rule, and sometimes by strong smell--so very easily fertilized also--that we should expect many natural hybrids in the genus. They are not forthcoming, however. Reichenbach displayed his scientific instinct by suggesting that two species submitted to him might probably be the issue of parents named; since that date Seden has produced both of them from the crosses which Reichenbach indicated.
We have three natural hybrids among Phaloenopsis. _Ph. intermedia_ made its appearance in a lot of _Ph. Aphrodite_, imported 1852. M. Porte, a French trader, brought home two in 1861; they were somewhat different, and he gave them his name. Messrs. Low imported several in 1874, one of which, being different again, was called after Mr. Brymer. Three have been found since, always among _Ph. Aphrodite_; the finest known is possessed by Lord Rothschild. That these were natural hybrids could not be doubted; Seden crossed _Ph. Aphrodite_ with _Ph. rosea_, and proved it. Our garden hybrids are two: _Ph. F.L. Ames_, obtained from _Ph. amabilis × Ph. intermedia_, and _Ph. Harriettæ_ from _Ph. amabilis × Ph. violacea_, named after the daughter of Hon. Erastus Corning, of Albany, U.S.A.
Oncidiums yield only two natural hybrids at present, and those uncertain; others are suspected. We have no garden hybrids, I believe, as yet. So it is with Odontoglossums, as has been said, but in the natural state they cross so freely that a large proportion of the species may probably be hybrids. I allude to this hereafter.
I have left Cypripediums to the last, in these hasty notes, because that supremely interesting genus demands more than a record of dry facts. Darwin pointed out that Cypripedium represents the primitive form of orchid. He was acquainted with no links connecting it with the later and more complicated genera; some have been discovered since that day, but it is nevertheless true that "an enormous extinction must have swept away a multitude of intermediate forms, and left this single genus as the record of a former and more simple state of the great orchidacean order." The geographical distribution shows that Cypripedium was more common in early times--to speak vaguely--and covered an area yet more extensive than now. And the process of extermination is still working, as with other primitive types.