22 
TIDE-BORNE SEEDS, ETC. 
is the effect of the general motion to which the surface of 
the ocean is subjected at its western extremity. Wo shall 
give but a. very succinct account of the arm of the Gulf- 
stream, which in the 45th and 50th degrees of latitude, near 
the bank called the Bonnet Flamand, runs from south-west 
to north-oast towards the coasts of Europe. This partial 
current becomes very strong at those times when the west 
winds are of long continuance: and, like that which flows 
along the isles ol I'erro and Gomera, it deposits every year 
on the western coasts of Ireland and Norway the fruit of 
trees which belong to the torrid zone of America. On the 
shores ot the Hebrides, we collect seeds of Mimosa scandens, 
ot Doliclios urens, of Guilandina bondue, and several other 
plants of Jamaica, the isle of Cuba, and of the neighbour- 
ing continent. The current carries thither also barrels of 
French wine, well preserved, the remains of the cargoes of 
vessels wrecked in the "West Indian seas. To these examples 
of the distant migration of the vegetable world, others no 
less striking may be added. The wreck of an English vessel, 
the Tilbury, burnt near Jamaica, was found on the coast of 
Scotland. On these same coasts are sometimes found various 
kinds of tortoises, that inhabit the waters of the Antilles. 
IV hen the western winds are of long duration, a current is 
formed in tho high latitudes, which runs directly towards 
east-south-east, from the coasts of Greenland and Labrador, 
as far as the north of Scotland. Wallace relates, that twice 
(in 1682 and 1684), American savages of the race of the 
Esquimaux, driven out to sea in their leathern canoes, during 
a storm, and left to the guidance of the currents, reached 
the Orkneys. This last example is the more worthy of 
attention, as it proves at the same time how, at a period 
wl.f:n tho art of navigation was yet in its infancy, the motion 
A- tho waters of the ocean may have contributed to disse- 
minate the different races of men over the face of the globe. 
, In reflecting on the causes of tho Atlantic currents, wo 
find that they are much more numerous than is generally 
believed ; for the waters of the sea may be put in motion by 
an external impulse, by difference of beat and saltness, bj 
the periodical melting of tho polar ice, cr by the inequality 
of evaporation, in different latitudes. Sometimes several o’i 
these causes concur to one and the same effect, and some- 
