DISPERSAL OF PLANTS BY OCEAN CURRENTS. 73 
occurrence in the drift, it is interesting to note that on the eastern, 
or weather, side of the island, where they are washed up, there is not 
a single coconut grove near the water's edge, while on the western, or 
lee, side, where groves have been planted, they grow so near the sea 
that their roots are often bared by the waves. It seems probable that 
coconuts grow in Guam only where they have been planted, except 
in cases where nuts which have fallen from trees of established groves 
have taken root. 
The seeds which occur in the drift owe their buoyancy to various 
causes. Many of the ‘*sea beans” inclose an air space between their 
cotyledons; others have kernels which do not fill the stony, water-tight 
shells, but leave a space for air to keep them afloat: others have a 
separate air chamber; others have fibrous envelopes or husks com- 
posed of light tissue, and still others have woody or cork-like shells of 
low specific gravity. 
SEA BEANS ADAPTED FOR FLOATING.—Among the hard stony seeds 
of leguminous plants cast up on the shores of Guam are gray ** nicker- 
nuts” (Guiland/na ecrista), called ** pakao” by the Guam natives; 
hrown ‘‘horse-eye sea beans” (St/20l0b/1m giganteum), with a con- 
spicuous black raphe encircling nearly three-quarters of the periphery 
of the seed, and the large flat ‘*snuftfbox beans” (Lens phascoloides), 
mulled ** bayog” or “badyog” in Guam and **cacoons” in the West 
Indies. These ‘*sea beans,” or their closely allied representatives 
crowing in the West Indies, were figured as early as 1693 in an 
account of the objects cast up by the sea on the Orkney Islands by 
James Wallace, who knew nothing of their origin.” They were 
recognized at once by Hans Sloane as the seeds of plants he had 
seen growing in Jamaica and which he had included in his catalogue 
of Jamaica plants. Their occurrence on the shores where they were 
collected, so far removed from the place of their origin, suggested 
to Sloane the existence of the current which was afterwards a 1iown 
as the Gulf Stream. Sloane published a paper on the subject in the 
Philosophical Transactions of London in 1696, in which he for the 
first time offered to the world the true explanation of the means by 
whic ‘h they were transported.” 
«* Cast up on the Shoar there are very oft those pretty Nutts, of whic h they use to 
make Snuff-boxes. There are four sorts of them, the figures of which are set down.” 
Deseription Orkney Islands, p. 14, 1693. 
b How these several Beans should come to the Scotch Isles, and one of them to 
Ireland, seems very hard to determine. It is easy to conceive, that growing in 
Jamaica in the Woods, they may either fall from the Trees into the Rivers or be any 
other way conveyed by them into the Sea: it is likewise easie to believe, that being 
got to Sea, and floating in it in the neighbourhood of that island, they may be ear- 
ried from thence by the Wind and Current, which meeting with a stop on the main 
continent of Am. is forced through the Gulph of Florida, or Canal of Bahama, going 
there constantly KE. and into the N. American Sea; for the ©... Sargasso grows on” 
