Ridley .— The Distribution of Plants . 25 
four species in the Malay Peninsula, all inland plants and endemic, except 
one reaching to Cochin China, and one of rather dubious distribution to the 
Malay Islands, and the maritime C. inophyllum , Linn., ranging from Africa, 
through India, Ceylon, and the Malay region, including Christmas Island, 
to Australia and Polynesia. 
Hcritiera elata , Ridl. (Sterculiaceae), is a rare tree in Singapore forests 
only. H. littoralis , Dryand., inhabits tidal swamps and sea-shores, common 
over the whole of tropical Asia. H. elata has no means of dispersal except 
rolling of the fruits. f tree which fruited heavily was surrounded the 
following year with hundreds of seedlings, next year the number had largely 
diminished, till in three or four years hardly one had survived. H. littoralis 
has seeds modified for floating in the sea, and I have never seen it so heavily 
fruiting, yet it is far more widely distributed than the jungle tree. 
Sophora (Leguminosae) is a genus of about fifty inland species rangingover 
the tropics and subtropics, all species local and of limited distribution, except 
N. tomentosa , Linn., a maritime species with sea-borne seeds, with a distri¬ 
bution over Florida, West Indies, Brazil, and the whole of Asia and Africa. 
Scaevola (Goodenoviae) contains about fifty species confined to 
Australia, a few in New Zealand and Polynesia, one in China, and a few in 
the eastern Malay Archipelago. These are not sea-dispersed plants and 
are all very local. N. Koenigii> Vahl., a fleshy sea-shore shrub with fruits 
adapted for sea-dispersal, is common on the coasts of Mauritius, India, 
Ceylon, Siam, China, Formosa, Malay Peninsula and Archipelago, includ¬ 
ing Christmas Island, and Polynesia, a far wider distribution than all the 
rest of the genus put together. 
Derris , Linn., is a genus of Leguminosae widely spread over Asia, but 
more or less local. Most of the species have thin, indehiscent, one-sided 
pods, drifted to a short distance by wind, and inhabit inland forests and 
plains. 
Derris thyrsiflora , Benth., is found in low, open country; its pods are 
blown to about sixty yards from the plant by wind. It is confined to the 
Malay Peninsula as far north as Mergui, and Sumatra and Java. Closely 
allied to it is D. sinuata , Thw., a tidal-river plant with pods which bear 
several seeds and break up into joints and are sea-dispersed. It is distri¬ 
buted over Ceylon, Burma, the Malay Peninsula, and Borneo, a wider area 
than that of D. thyrsiflora. D. idiginosa , Benth., is a sea-shore species with 
pods specially adapted for sea-dispersal. It occurs from P^ast Africa and 
the Mascarene Islands on all the Asiatic coasts to China and Japan, Formosa, 
Australia, and Polynesia. No other species of the genus has anything like 
this distribution, most being quite local. D. scandens , Benth., however, a sea¬ 
shore and river plant, occurs on most of the Asiatic coasts. 
Pemphis acidula , Forst. (Lythrarieae), a monotypic genus, and Tourne- 
fortia argentea , Linn. fil. (Boragineae), have a distribution from the 
