2 PLANTS, SEEDS, AND CURRENTS 



The Sifting Process. — This sifting out of the less buoyant 

 materials is well illustrated when we compare the vegetable drift 

 thrown up on the small islands of the Turks Group with that deposited 

 on the beaches of the larger islands in the neighbourhood of estuaries, 

 as in the case of the Orinoco drift piled up on the south side of Trinidad, 

 or, to take a less conspicuous example, of the drift stranded on the 

 south coast of Jamaica in the vicinity of the Black River. These 

 matters will be mentioned in a later page; but here it may be said 

 that the foreign drift, which makes up nearly all of the larger materials 

 stranded on the Turks Islands, presents us with the seeds and fruits 

 that are most likely to be carried in the Gulf Stream across the 

 Atlantic. The beach-drift of this small group displays the West 

 Indian drift in transit at an early stage of the North Atlantic traverse. 



If we desired to know what seeds and fruits of the floating drift 

 of the West Indian seas we ought to find on the shores of Europe, 

 we must look for them, not on the beaches of the larger islands where 

 they would be mixed with and sometimes lost among a mass of 

 vegetable materials of local origin, but on the coast of some low, 

 scantily vegetated, outlying islet standing well removed from the main 

 islands. Such an islet would receive on its beaches a sample of the 

 drift after it has lost all the less buoyant constituents during a 

 flotation of some weeks in the open ocean. These are just the oppor- 

 tunities which are offered in the several small islands and islets of 

 the Turks Group. Here in sample we see the oceanic drift that is 

 carried swiftly by the Gulf Stream through the Florida Channel and 

 then past Cape Hatteras eastward to the shores of Europe. 



General Description of Drift. — With this object in view I will 

 at first generally describe West Indian beach-drift, referring in passing 

 to some of its special characters in particular localities. 



In the West Indies, as elsewhere, the local drift is generally pre- 

 dominant, that is to say, the drift derived from plants growing in the 

 vicinity, whether at the border of the beaches, or in the coastal and 

 estuarine mangrove swamps, or in the interior along the sides of 

 rivers. It is from the beaches near a large estuary that we can 

 form the best idea of the nature of the materials that any particular 

 region supplies to the currents for oceanic transport. If we confined 

 our attention entirely to the drift brought down by rivers, or to the 

 materials supplied by shore vegetation, our conception of its general 

 composition would be incomplete. It is on a beach near an estuary, 

 where the seeds and fruits derived from the beach plants are mingled ' 

 with those from the mangrove vegetation and from the riverside 

 plants of the interior, that we can learn our lesson concerning local 

 drift. 



Yet this would take no cognisance of the foreign drift, the materials 

 brought from a distance, often from a continental coast or from some 

 island hundreds of miles away. This is liable to be masked by the 

 local drift on a beach near an estuary. It is best sought for and 

 most easily recognised on some long stretch of beach far from an 

 estuary, since it is often not difficult there to differentiate between 

 it and the drift supplied by the beach vegetation. But here again 

 obstacles may arise. Some knowledge of the flora must be acquired, 



