Ridley.— On Endemism and the Mutation Theory . 555 
Strophanthus Maingayi, Hook. fil. ‘Climbing extensively over trees’, 
Maingay. This beautiful plant, with white flowers as big as a wine-glass it 
is said, was again collected by Hullett at Changi before 1888. I visited the 
spot where he found it with him, but it was gone and has never been seen 
again anywhere. 
Melastoma molle , Wall. Collected in Singapore by Wallich, 1822, 
reduced to a variety of M. decemfidum , Roxb., by Clarke, but certainly 
distinct, reported to have been obtained in Luzon by Cuming. I found 
a single small plant without any signs of flowers in dense jungle on Bukit 
Timah. The plant had disappeared on my next visit, and it has not been 
seen again anywhere. 
Endopogon Ridleyi , Clarke. The whole of the country lying north-west of 
Bukit Timah has long been felled and cleared. It was being felled for timber 
in Wallace’s time, 1854, as described by him in his ‘ Malay Archipelago \ 
There remained, however, a small patch of wood through which ran a small 
stream ; on its banks grew abundance of Endopogon Ridleyi , and near it grew 
a fine Ginger, Zingiber chryseum , Ridley. In 1911 this patch of jungle was 
felled and burnt, and both species are probably now extinct. 
Pinanga singaporensis , Ridl., grew in another patch of wood surrounded 
by extensive cultivated land. I have failed to find it anywhere else. 
Probably on account of the limited number of plants occurring here, and 
consequent want of cross-fertilization, it did not set fruit, and this wood was 
destroyed some years later. 
Didymocarpus Perdita , Ridley. I found two plants of this on a bank 
in the centre of Singapore surrounded by extensive cultivation. It has 
never been seen again. 
Euthemis minor , Jack., was described by him from Singapore, 
apparently common in 1820-2. After much search I discovered a single 
patch in the farther corner of Singapore. It is a sea-coast plant of the 
south of Singapore, but the greater part of the sea-coasts have long been 
cleared of their endemic vegetation. 
Close to the Botanic Gardens stand no less than three unique trees, the 
remains of high forest formerly covering the ground, left because they were 
too high to destroy. Usually in this case the tree soon dies because of the 
exposure of its roots to the hot sun ; these trees being better placed have 
survived. They are Shorea gibbosa i Brandis, Parishia sp., a male tree only, 
and Ormosia macrodisca , Bak. ; this latter is said to occur in Sumatra, and 
there is a tree in the Buitenzorg Gardens. Otherwise no other trees of 
these species are known, and, as so often happens in cases of isolated trees, 
they failed to produce any healthy offspring. 
In 1889 in the Kranji Mangrove swamps I found on the trees no less 
than forty-six species of Orchids in abundance. In 1915 I visited these 
swamps again to look for them, and could only find four or five of the 
