Part III.] OR POISONED BY VEGETABLE GROWTH? 
169 
diterranean.” Here distance and prior occu¬ 
pancy seem to take the duties of natural bar¬ 
riers. But however small, and however com¬ 
paratively modern the spot, if it be inclosed by 
natural barriers (as, for instance, St. Helena) it 
will apparently have a creation for itself. 
So in the Galapagos islands, of which there 
are ten principal islands, under the line, 600 
miles westward of America, of modern origin, 
judging from the fresh appearance of about 
2000 craters, Lyell says of them : “ Although 
each small island is not more than fifty or sixty 
miles apart, and most of them are in sight of 
each other, formed of precisely the same rock, 
rising nearly to an equal height, and placed 
under a similar climate, they are tenanted each 
by a different set of beings“Of twenty-six 
different species of land birds found in the Gala¬ 
pagos archipelago, all, with the exception of one, 
are distinct from those inhabiting other parts of 
the globe; and in other archipelagoes a single 
island sometimes contains a species found in no 
other spot on the whole earth.” Wings them¬ 
selves furnish no exception to the rule. The 
Creator hangs his cages containing distinct birds 
in distinct separate regions, though those dis¬ 
tinct separate regions may have precisely the 
same physical conditions. Lyell quotes Darwin : 
