36o NOTES OF A BOTANIST 
a plant which serves as food for any particular 
animal or tribe of animals in a given locality is 
pretty certain to have its congener (or at least its 
co-ordinate) in any other locality of the same 
region. 
The riparial plants of the Amazon (such, namely, 
as grow between ebb- and flood-mark, or within the 
limits to which the annual inundations extend) 
range in many instances from the very mouth of 
the river up to the roots of the Andes ; ar?d I do 
not yet know of a single tree which is not found 
both on the northern or Guayana shore and on the 
southern or Brazilian.^ The most notable example 
of this extensive range is the Pao Mulatto or 
Mulatto tree (Enkylista, Benth.), a tall, elegant 
tree allied to the Cinchonas, and conspicuous from 
its deciduous brown bark, which grows everywhere 
on lands flooded by the Amazon, and, from its 
accessibility and the readiness with which its wood 
burns while green, supplies a great part of the fuel 
consumed by the steamers that navigate the Amazon. 
It is almost equally common on some of the white- 
water tributaries ; I have seen it, for instance, far 
away up the Huallaga to the south, and up the 
Pastasa to the north. Two of the commonest 
river-side Ingas of the Amazon (/. splendens, W., 
and /. coryinbifera, Benth.) reappear together on 
the Upper Casiquiari and Orinoco ; and similar 
instances might be multiplied indefinitely. 
Streams of black or clear water have also their 
proper riparial vegetation, some species being 
^ Hence I suspect that those insects of the south side of the Amazon which 
have been identified with Guayana species belong chiefly to the riparial 
forests. 
