JULY, 1908.] THE ORCHID REVIEW. 219 
three others the sexes are much alike in size and shape, but in the rest of 
the species the remarkable diversity just pointed out is seen, the lip in the 
two sexes being very different in shape, the males much smaller than the 
females, and the perianth always membranous. Here we reach the culmin- 
ating point of development among the Orchidacee in this direction. 
All these, and numerous other remarkable developments of floral 
structure are adaptations to secure the visits of useful insects, for purposes 
of cross fertilisation, or to exclude others who would only plunder the 
flowers without effecting this, and if we would understand the reasons why 
such complex means have been adopted to secure such an apparently simple 
end, we can find an answer in the beneficial effects of cross fertilisation. 
Continued self fertilisation is well known to bé injurious, and all these 
elaborate means to prevent it have gradually arisen according to the neces- 
sities of the case. Any adaptation which served to increase fertility would 
tend to be preserved and perpetuated, while variations in the contrary 
direction would be eliminated in the struggle for existence. The process is 
known under the expressive term “‘ natural selection,” and under its agency 
has arisen those distinct races known to us as “ species,’’ and I think we 
must all admit that the origin of species—at all events among Orchids—is 
a very fascinating study. 
Pee 
ORCHIDS AT KEW. 
A NUMBER ot rare and interesting Orchids are in flower in the Kew collec- 
tion. In one of the houses may be seen a good plant of Acineta Hum- 
boldtii, the handsome Scuticaria Steelii, Stanhopea guttulata, some fine 
Thunias, including the richly-coloured T. Winniana, a fine plant of Cirr- 
hopetalum robustum, Ansellia gigantea, Oncidium Lanceanum, Phaius x 
Phcebe, Brassavola Digbyana, Eulophia euglossa, Epidendrum fragrans, 
Liparis odorata, elata and guineensis, Nephelaphyllum pulchrum and 
cristatum, Polystachya leonensis, laxiflora and bicolor, and other botanical 
Orchids. - 
In the adjacent Cattleya house is a fine Epidendrum cochleatum, the 
striking E. trachychilum, E. pentotis, E. variegatum, E. X O’Brienianum, 
with its two parents, E. radicans and E. evectum, the brilliant E. vitel- 
linum, a fine plant of Stanhopea tigrina, the rare Gongora gratulabunda, 
Sobralia Amesiana and macrantha, Oncidium maizefolium, unicorne, sar- 
codes, Wentworthianum and graminifolium, with other interesting things. 
The Cool house is gay with numerous Odontoglossum crispum, examples 
of O. Pescatorei, triumphans, gloriosum, grande, Uroskinneri, Harryanum, 
luteopurpureum, sceptrum, Lindleyanum, X crispo-Harryanum, and several 
others, together with Oncidium serratum, macranthum, and candidum, 
Miltonia vexillaria and M. x St. Andre, Cochlioda Neetzliana, a very fine 
