FOREIGN DRIFT OF THE TURKS ISLANDS 143 



may be made. They were included in the drift collection made by 

 Morris on the south coast of Jamaica (Chall. Bot., IV., 299), but 

 nothing is said as to their condition. As the plant is not known 

 from this island, the seeds were probably brought by the Equatorial 

 Current in its passage across the Caribbean Sea. The seeds often 

 came under my notice on the beaches of Trinidad, where the tree 

 is at home. On the south coast very few of them were in a sound, 

 fresh condition, many of them showing evidence of prolonged flota- 

 tion in the sea in the incrusting shells of cirripedes and of other 

 marine organisms, whilst others had been probably brought down 

 by the Orinoco, since they were in a germinating but dried-up con- 

 dition. On the north coast, as at Grande Riviere, they were more or 

 less fresh, and had evidently been recently brought down by the 

 river. They were frequent on the east coast of Tobago, often 

 incrusted by cirripedes ; but as far as I know the plant is not found 

 in the island. In the Turks Islands they mostly came under my 

 notice on the east side of Grand Turk, half of them being empty, 

 whilst not more than one in ten possessed sound seeds. 



Of the four West Indian localities above mentioned which dis- 

 played the fruits of Carapa guianensis in the beach-drift — namely, 

 Jamaica, Trinidad, Tobago, and Turks Islands, only the second as 

 far as I know owns the parent plant. But from the regular occur- 

 rence of the seeds in the drift of the Turks Islands, where the tree 

 certainly does not grow, it may be inferred that the species is at 

 home in the islands to the southward and eastward (San Domingo, 

 Porto Rico, etc.), from which the drift seems to be largely derived. 

 According to the writings of Grisebach, Hemsley, Spruce, and 

 Schimper, the tree grows on the mainland at the coasts and in the 

 estuaries of Central America, Venezuela, the Guianas, and Brazil. 



The fact that Carapa guianensis also grows on the coast of Sene- 

 gambia in West Africa raises the issue as to the seed's capacity of 

 crossing the Atlantic in a germinable state. Although the seeds 

 will evidently float for many months in the sea, from the indications 

 above given it is doubtful whether they would retain their germina- 

 tive powers for so long a period. The risks, as I have shown, are 

 great and numerous. It is especially questionable whether the seeds 

 would withstand a sea passage of more than two or three months, 

 or, in other words, whether for the purpose of effective dispersal 

 they are fit for much more than distribution by the currents over 

 the islands of the Caribbean Sea. This would quite exclude the 

 possibility of their being able to reach in a sound state the tropical 

 coasts of West Africa from the New World by the Gulf Stream 

 route, which even by the way of the Azores would occupy twelve 

 months and more. But, as we have seen, Carapa is mainly an Old 

 World genus, the New World being presumably the recipient rather 

 than the distributor. In that event it is quite possible that the 

 seeds could accomplish the much shorter ocean passage, occupying 

 only three or four months, in the stream of the Main Equatorial 

 Current from the Gulf of Guinea to the coast of Brazil, a subject 

 discussed in Chapter III. The fact that seeds of Carapa moluccensis 

 are often cast up in the fresh condition on the shores of Keeling 



