360 NOTES OF A BOTANIST CHAP. 



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 ; and 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. 1 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 (I. splendens, W., 

 and /. corymbifera, 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 



1 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 



fi ircsts. 



