ON THE DISPERSAL OF PLANTS. 3805 
collected in the autumn of 1888 amongst the drift thrown up on the 
Keeling beaches. They were all still floating in the first week of 
June, 1891, and were seemingly as buoyant as ever. Five seeds of 
Morinda citrifolia, a seed of Thespesia populnea, two fruits of Sewvola 
Koenigit, a fruit of Cordia subcordata, and a seed of Ipomea grandi- 
flora, all obtained in the fresh condition in September, 1888, from 
their respective plants in the Keeling Islands, were placed in sea- 
water on June 8th, 1890, and were still afloat just twelve months 
afterwards, in June, 1891, apparently unharmed. Four fruits 
of Tournefortia argentea (from Keeling plants) that 1 picked up 
from the ground in September, 1888, remained afloat in sea-water 
in June, 1891, after being just twelve months in the water. 
Five seeds of Tacca pinnatifida from a fruit that I picked off a plant 
on the coast of Java in November, 1888, were placed in sea-water 
on June 8th, 1890, and are still afloat after an interval of twelve 
months. When I obtained the fresh fruits I noted that they floated 
heavily in sea-water, while their seeds sank. ‘Two pods of Pongamia 
glabra, found washed up on the Java coast in December, 1888, were 
placed in sea-water on June 8th, 1890; one sank after 125 days, 
and the second floated 202 days before sinking. Three seeds of 
Hibiscus tiliaceus, obtained from a tree on the Keeling Islands in 
September, 1888, were placed in sea-water on July 20th, 1890 ; the 
first sank on September 18th, 1890, the seeond early in February, 
1891, and the third in the second week of March, 1891, A single 
Teak fruit (Tectona grandis) from Java has now been floating just 
twelve months, having been kept dry previously for nearly two years, 
The beans of three or four species of Mueuna, collected by me in the 
vegetable drift of the beaches of the Keeling Islands and of the 
Java coast during the latter part of 1888, were placed in sea-water 
in June, 1890; but their powers of flotation varied greatly, three 
beans of one species sinking in from three to eight days, two 
beans of another species sinking in from 60 to 100 days, whilst two 
beans belonging to other species are still floating buoyantly after 
twelve months in the water. I have remarked in my paper that the 
seeds of Suriana maritima sink in a few days, but I should have said 
“fresh” seeds. Six seeds that I had by me for over two years, 
seeds obtained from the identical tree to which the fresh ones 
belonged, were placed in sea-water on March 9th, 1891, and four of 
them were still afloat about four months afterwards. Three seeds 
of Coix lachryma, obtained in the Solomon Islands in 1884, floated 
only from two to six days in sea-water in 1891. (The sea-water in 
