62 PLANT MIGRATION 
riverside and seaside plants; and no doubt their dis- 
persal is to a great extent due to streams and tidal 
currents. But the majority of the hundreds of 
thousands of seeds which a river transports annually 
find their last resting-place in quiet backwaters or on 
the floor of the sea. 
It is different, however, with the flora which fringes 
beaches in the Tropics. Here many of the plants 
possess large fruits of great buoyancy, which are still 
afloat and alive after months of tossing on the waves, 
and if cast up germinate readily. These bold 
wanderers are a familiar feature of Tropic plant life, 
and their successful voyaging accounts for the uni- 
formity of the beach flora on innumerable islands. 
Even our own inhospitable shores sometimes receive 
these waifs of warmer seas, brought from the West 
Indies by the Gulf Stream and the prevailing south- 
west winds. Of these the most frequent are the large 
bean-like seeds of Entada scandens, a Leguminous 
plant, which are originally enclosed in gigantic pods 
several feet in length, and the more globular seeds of 
the Bonduc (Guilandina bonducella), another species 
of the same order. But the most famous of all float- 
ing fruits is the Double Cocoanut, or Coco-de-mer, a 
huge nut weighing 40 or 50 lb. and containing several 
seeds a foot and a half long. It is the product of a 
Palm (Lodoicea Sechellarum); cast up on the shores 
of India, it was known centuries before its place 
of origin in the Seychelles was discovered, and 
fantastic legends grew up regarding it. 
3. Wind—Everything that we know about the wind 
suggests that it is a potent agent of seed-dispersal, 
far excelling, for instance, that of flowing water. “ All 
