58 THE WORLD OF LIFE 



To any one but me and yourself, this estimation will appear 

 most extravagant, for even Martius (if I recollect rightly) emits 

 an opinion that the forests of the Amazon contain but few 

 species. But allowing even a greater repetition of species 

 than I have ever encountered, there cannot remain less than 

 at least half the above number of species undiscovered." 1 



Spruce was one of the most careful and thoughtful of 

 writers, and would never have made such a statement without 

 full consideration and after weighing all the probabilities. 

 In the same letter he describes how, when leaving the 

 Uaupes River after nine months of assiduous collecting there 

 in a very limited area, a sunny day after continuous rains 

 brought out numerous flowers, so that as he floated down 

 the stream he saw numbers of species quite new to him, 

 till the sight became so painful that he closed his eyes to 

 avoid seeing the floral treasures he was obliged to leave 

 ungathered ! At Tarapoto he observed that some flowers 

 opened after sunset and dropped off at dawn, so that they 

 would be overlooked by most collectors, while of many the 

 flowering season was very limited, sometimes to a single 

 day. Join to this the scarcity of individuals of many species 

 scattered through a trackless forest, and it is evident 

 that the true floral riches of these countries will not be fully 

 appreciated till numerous resident botanists are spread over 

 the entire area. 



From the facts of distribution given by Mr. Hemsley 

 we learn that about one-twelfth of the species of Central 

 America are found also in South America, and that about 

 7CO are found in the eastern portion from Venezuela to 

 Brazil, so that probably not more than 500 reach the 

 latter country. The combined floras of Brazil and Central 

 America, even as now imperfectly known, will therefore 

 reach about 34,300 species. Now, considering how very 

 rich the eastern slopes of the Andes are known to be, and 

 that the average width of the forest zone between Brazil 

 and the Andes is from 400 to 500 miles, while the plateaux 

 and western slopes also have a rich and distinct flora and 

 fauna, I think it will be admitted, that whatever the 

 combined floras of Brazil and Central America may amount 



1 See Spruce's Notes of a Botanist on the Amazon and Andes, vol. ii. p. 208. 



