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to Pasco, prefaced by some general observations on the 

 climate of Chili and the western side of Peru. By bringing 

 into one view a number of facts connected with the latter 

 subject, some useful hints may be derived for the cultivation 

 of plants from that part of the world ; many species from 

 thence being now common in our collections, and the number 

 is constantly increasing, but their treatment is not always 

 consistent with their natural habits. At the same time, as 

 it is probable that the western side of South America will be 

 more frequently visited by Europaeau Botanists than formerly, it 

 becomes a matter of some interest to know the best season of 

 the year for exploring the different districts, especially where 

 there is so much difficulty, at certain seasons, in travelling 

 from one point to another. For want of previous informa- 

 tion on this head, much valuable time has been lost by 

 collectors arriving at different parts of the coast, when 

 scarcely a plant was to be found in flower, and the weather 

 would not allow of travelling in the interior. In the account 

 of the road to Pasco, I will endeavour to give some idea of 

 the sort of country that produced the few plants I was able 

 to collect for you ; but you are aware, that I was in very bad 

 health during my stay in Peru, and my observations were 

 necessarily very limited. 



Chili, and that part of Peru lying west of the Andes, from 

 their geographical situation and physical structure, offer an 

 interesting field for studying the effect of climate on vegeta- 

 tion. The two countries present a line of coast, extending 

 from 40° of South latitude, to within a few degrees of the 

 Equator ; the great chain of the Andes runs in a direction 

 almost parallel to the coast, and the surface of the inter- 

 mediate country is similar throughout, consisting of ranges 

 of mountains, diminishing in height as they recede from the 

 Cordillera. These mountains are intersected by vallies 

 nearly at right angles to the great chain, and consequently 

 varying little from due east and west, so that, while the 

 coast is exposed to the action of those laws that regulate 

 climate according to the difference of latitude at the level of 

 the sea, the vallies afford an opportunity of tracing the 



