AMAZONIAN VEGETATION 359 
great Amazonian forest -belt, wherein they now 
barely exist on the bits of campos that at wide 
intervals break the monotony of the w^oodland — 
although they probably at some antecedent period 
ranged continuously from north to south. 
In other cases, closely allied species occupy 
distinct areas. One of the finest fruits of Equatorial 
America, the Cocura (Pourouma of Aublet), is borne 
in large grape-like bunches on trees of the Bread- 
fruit tribe, having large, palmatifid, hoary leaves, 
quite like those of their near allies the Cecropias. 
Now the Cocura of the mid-region of the Rio 
Negro, of the Japura, and of the Upper Amazon 
or Solimoes is one species {^Pourouma cecropicB folia, 
Mart.), while that of the mouth of the Rio Negro 
and adjacent parts of the Amazon is a very distinct 
and smaller-fruited species (/^. rehtsa. Spruce), and 
that of the Uaupes is a third species {P. apiculata, 
Spruce), all three being so plainly diverse that the 
Indians distinguish them by adjective names, 
although that diversity or divergence, as in a great 
many parallel instances, is but a measure of the time 
that has elapsed since their derivation from a single 
stirp. 
But the most general cause of resemblance lies 
in this fact, that there are many orders and families 
of plants whereof many of the species are confined 
to limited areas, and yet, throughout the Amazon 
valley, each order, or family, will be everywhere 
represented by about the same number of indi- 
viduals and species, having to each other nearly 
the same correlation, as regards aspect and sensible 
properties, provided always that the conditions of 
growth (as above defined) be the same ; so that 
