WEST INDIAN BEACH-DRIFT 



5 



On the other hand, with the associates of the mangroves the floating 

 fruit or seed has many difficulties to contend with that considerably 

 restrict its capacities for distribution. Thus the seeds of Anona 

 palustris and of Carapa guianensis are very apt to germinate when 

 afloat in river-drift ; and my observations indicate that the germinat- 

 ing seed would soon be killed when it reached the sea-water, though 

 the dead seed might float a long time and be thrown up in a more 

 or less empty or unsound condition on some distant shore. So again 

 with Manicaria saccifera, the seeds do not seem to be able to with- 

 stand sea- water immersion for a long period, though the fruit with a 

 decaying or dead seed may be transported by the currents for a great 

 distance. Sacoglottis amazonica is rather better adapted in these 

 respects, 



Drift supplied by the Plants of the Beach and its Borders. — 

 In the last place we will deal with the plants of the beach and its 

 borders that add their buoyant seeds and fruits to the drift of the West 

 Indian seas. Those which are most generally distributed, being 

 those which are most characteristic of the drift, are enumerated below. 

 In point of size the drift derived from beach plants in the West 

 Indies offers a great contrast to that supplied by the beach vegetation 

 of the tropical islands of the Indian and Pacific oceans. In the West 

 Indies we miss the large fruits of Barringtonia speciosa, Cerbera cdol- 

 lam, Ochrosia parri flora, Heritiera littoralis, Cycas circinalis, Pandanus, 

 etc., trees that give character to the vegetation of the beaches of 

 many an island and many a tract of continental coast in those oceans. 

 The largest fruits of the common West Indian beach-drift, such as 

 those of the Manchineel (Hippomane mancinella), Thespesia popv.lnea, 

 and Ecastaphyllum brozvnei, are not more than lj inches (37 mm.) 

 across ; and most of the other plants contribute seeds and seed-like 

 fruits varying from a sixth to three-quarters of an inch (4-18 mm.) 

 in size. 



The Beach Plants commonly represented in the Floating 

 and Beach Drift of the West Indies. 



(One or two of the plants, like Conocarpus erectus, are perhaps most 

 characteristic of the borders of the mangrove swamps, but since they 

 thrive also amongst the vegetation bordering the beach they are here 

 included.) 



Canavalia obtusifolia (seeds). 

 Chrysobalanas icaco (stones). 

 Coccoloba uvifera (stone-like fruits). 

 Colubrina asiatica (seeds). 

 Conocarpus erectus (achenes). 

 Ecastaphyllum brownei (legumes). 

 Guilandina bonducella (seeds). 

 Hibiscus tiliaceus (seeds). 

 Hippomane mancinella (stones). 

 Tpomoea pes-caprce (seeds). 

 Scoeiola plumieri (stones). 



