ch. v.:

BY RIVERS AND CURRENTS.

35

moreover, indigenous to America and the West Indies ,such as that of the Mimosa scandens, the cashew-nut,and others, have been known to be drifted across theAtlantic by the Gulf stream , on the western coasts ofEurope , in such a state that they might have vegetatedhad the climate and soil been favourable. Amongthese the Guilandina Bonduc, a leguminous plant, isparticularly mentioned, as having been raised from aseed found on the west coast of Ireland. *

Sir Hans Sloane states, that several kinds of beanscast ashore on the Orkney Isles , and the coast of Ire­ land , are derived from trees which grow in the West Indies , and many of them in Jamaica . He conjecturesthat they may have been conveyed by rivers into thesea, and then by the Gulf stream to greater distances,in the same manner as the sea-weed called Lenticulamarina, or Sargasso, which grows on the rocks aboutJamaica , is known to be “ carried by the winds andcurrent towards the coast of Florida , and thence intothe North American ocean, where it lies very thick onthe surface of the sea.”f

The absence of liquid matter in the composition ofseeds renders them comparatively insensible to heatand cold, so that they may be carried without detri-ment through climates where the plants themselveswould instantly perish. Such is their power of resist-ing the effects of heat, that Spallanzani mentionssome seeds that germinated after having been boiledin water.J When, therefore, a strong gale, afterblowing violently off the land for a time, dies away,

* Brown, Append, to Tuckey, No. V. p. 481.f Phil. Trans., 1696.

| System of Physiological Botany, vol. ii. p, 403.

c 6