IV 



ZOOLOGY OF THE VOYAGE OF THE BEAGLE. 



great a change in latitude. Hence, although the vegetation of this northern 

 district presents a marked difference when compared with that of the southern ; 

 yet the zoology in many respects has, like the general aspect of the landscape, a 

 very uniform character. The specimens were chiefly collected from the Penin- 

 sula of Tres Montes, the Chonos Archipelago (from latitude 46° to 43° 30'), 

 Chiloe with the adjoining islets, and Valdivia. The contrast between the 

 physical conditions and productions of the East and West coasts of this part of 

 South America is very remarkable. On one side of the Cordillera, great heavy 

 clouds are driven along by the western gales in unbroken sheets, and the indented 

 land is clothed with thick forests ; whilst on the other side of this great range, a 



bright sky, with a clear and dry atmosphere, extends over wide and desolate 

 plains. 



Chile in the neighbourhood of Concepcion (latitude 36° 42' S.) may be called 

 a fertile land ; for it is diversified with fine woods, pasturage, and cultivated 

 fields. But towards the more central districts (near Valparaiso and Santiago) 

 although by the aid of irrigation, the soil in the valleys yields a most abundant 

 return, yet the appearance of the hills, thinly scattered with various kinds of 

 bushes and cylindrical Opuntias, bespeaks an arid climate. In winter, rain is 

 copious, but during a long summer of from six to eight months, a shower never 



* 



moistens the parched soil. The country has a very alpine character, and is 

 traversed by several chains of mountains extending parallel to the Andes. These 

 ranges include between them level basins, which appear once to have formed the 

 beds of ancient channels and bays, such as those now intersecting the land 

 further to the south. North of the neighbourhood of Valparaiso, the climate 

 rapidly becomes more and more arid, and the land in proportion desert. Beyond 

 the valley of Coquimbo (latitude 30°.) it is scarcely habitable, excepting in the 

 valleys of Guasco, Copiap6, and Paposa, which owe their entire fertility to the 

 system of irrigation, invented by the aboriginal Indians and followed by the 

 Spanish colonists. Northward of these places, the absolute desert of Atacama 

 forms a complete barrier, and eastward, the snow-clad chain of the Cordillera 

 separates the Zoological province of Chile, from that of the wide plains which 

 extend on the other side of the Andes. 



The last district which it is at all necessary for me to mention here, is that 



