28 THE VOYAGE OF H.M.S. CHALLENGER. 



includes the greatest possible variety of physical conditions. Beginning with Spitzbergen 

 and Nova Zembla, it may seem probable at first that their Arctic climate is too severe for 

 members of the orchid family ; yet, when we remember that Platanthera hyberborea, 

 Habenaria albida, and Listcra cordata are abundant and luxuriant on Disco Island, 

 Davis Strait, in about 69° 15' N. lat., climate does not adequately explain the absence of 

 orchids from the two first countries, because the warm oceanic current would more than 

 counterbalance the slight difference in latitude. Then, no fewer than thirteen species of 

 orchids are recorded from Iceland, where also a rigorous climate prevails. Some of the 

 species are extremely rare, however, and it is possible that the order is decreasing in 

 numbers and gradually disappearing from this flora. All the species inhabit Continental 

 Europe, and some of them have also a wide range in the Arctic zone. The Azorean orchids 

 are Serapias cordigera, a South European species, and two endemic species of Habenaria. 



The solitary Bermudan orchid is Spiranthes tortilis, a native of Jamaica and Antigua, 

 and a member of the most widely spread genus of the Orchideaj, if we except the somewhat 

 heterogeneous Habenaria. Spiranthes australis is perhaps the commonest and most 

 widely diffused species of orchid, ranging, as it does, from Afghanistan to Sachalin and 

 Japan, southward to Australia, New Caledonia, and New Zealand. 



Altogether there are eight species of orchids in Madeira and the Canaries, whereof 

 three are endemic and the rest Mediterranean. 



The four orchids occurring in the Falklands are Cldorcea gaudichaudii, Asarca 

 commersonii, Asarca odoratissima, and Codonorchis lessonii; the first being apparently 

 endemic, and the others South American. 



Socotra has now been pretty thoroughly explored, yet only one orchid, a species of 

 Habenaria, has been discovered ; but the adjacent countries are also poor in orchids. None 

 has been found at Aden, and the delta and valley of the Nile yield none. One only of the 

 five Rodriguez species is endemic ; and only two of the Seychelles species are endemic. 

 Seventy-four species are recorded from the Mauritius. 



Turning to the Pacific, the three orchids inhabiting the Sandwich Islands are endemic ; 

 they are all three terrestrial, and two of them belong to genera peculiar to the Malayan 

 Archipelago and Polynesia, while the third is a species of the widely spread Liparis, and 

 described as intermediate between Liparis IcBselii and Liparis liliifolia. 



Epridendrum spncatum, and an undetermined orchid, perhaps a species of Govenia, 

 collected by Captain "Wood, and preserved in the Kew Herbarium, are the only Gala- 

 pageian orchids at present known. The former is endemic, and the latter insufficient for 

 determination : both genera are otherwise exclusively American. We have seen no orchids 

 from any of the smaller islands of Eastern Polynesia, but there seems to be a fair 

 proportion in the larger — Tahiti, according to Nadeaud, possessing nineteen. 



That Juan Fernandez should possess none is surprising, considering the general 

 Chilian affinities of its vegetation. 



