FLORA OF TROPICAL SOUTH AMERICA. 35 



plants recorded are merely said to come from 

 " Columbia" or " Ecuador," the one larger than Spain, 

 France, and the Low Countries put together, the other 

 equal in extent to the Austrian Empire, and both 

 traversed by mountain ranges varying from fifteen 

 thousand to over eighteen thousand feet in height ? 

 I shall have later to make some remarks on the 

 climatal conditions of the coast region extending 

 from Panama to the Bay of Guayaquil, but I may here 

 mention that when I afterwards acquired some slight 

 acquaintance with the flora of Brazil, I was struck 

 with the fact that, although separated by an interval 

 of nearly three thousand miles, and by the great 

 barrier of the Andes, the plants seen in and around 

 the forest at Buenaventura were almost all nearly 

 allied to Brazilian forms. 



Further reflection, and such incomplete knowledge 

 as I have been able to acquire as to the flora of inter- 

 tropical South America, lead me to the conclusion 

 that the present vegetable population of this vast 

 region is, when we exclude from view a certain 

 number of immigrants from other regions, mainly 

 derived from two sources. There is, in the first 

 place, the ancient flora of Guiana and tropical Brazil, 

 which has gradually extended itself through Venezuela 

 and Columbia, and along the Pacific coast as far as 

 Ecuador, and, in an opposite direction, through 

 Southern Brazil, to the upper basins of the Uruguay, 

 the Parana, and the Paraguay. The long period of 

 time occupied by the gradual diffusion of this flora is 

 shown by the large number of peculiar species, and 

 not a few endemic genera that have been developed 



