433 



and joins the western chain, that of Caxamarca, 

 or the Nevados of Pelagatos and Huaylillas, 

 and forms the great knot of the mountains of 

 Loxa, The mean height of this knot is only 

 1000 to 1200 toises; its temperate climate 

 renders it peculiarly fitted for the vegetation 

 of the trees of quinquina, the finest kinds of 

 which grow in the celebrated forests of Caxa- 

 riuma and Uritusinga, between the Rio Zamora 

 and the Cachiyacu, and between Tavacona and 

 Guancabamba. For ages, before the quinquina 

 of Popayan and Santa Fe de Bogota (nor. 

 lat. 2i° to 5°), of Huacarachuco, Huamalies, 

 and Huanuco (south lat. 9° to 11°), was known, 

 the knot of the mountains of Loxa was regard- 

 ed as the sole region from whence the febrifuge 

 bark of Cinchona could be obtained. This 

 knot occupies the vast territory between Guan- 

 cabamba, Avayaca, Ona, and the ruined towns 

 of Zamora and Loyola, between 51° and 3i° of 

 latitude. Some of the summits (the Paramos 

 of Alpachaca, Saraguru, Savanilla, Gueringa, 

 Chulucanas, Guamani, and Yamoca, which I 

 measured), rise from 1580 to 1720 toises, but are 

 not as a groupe covered with snows, which in this 

 latitude falls only above 1860 to 1900 toises of 

 absolute height. In descending towards the 

 east, to the Rio Santiago and the Rio of Cha- 

 maya, two tributary streams of the Amazon, 

 the mountains lower rapidly ; between San 



2 g 2 



