48 SANTAREM. Chap. I. 



of 500 or 600 feet, and its ascent is excessively fatiguing 

 after the long walk from Santarem over the campos. I 

 tried it one day, but did not reach the summit. A dense 

 growth of coarse grasses clothed the steep sides of the 

 hill, with here and there a stunted tree of kinds found 

 in the plain beneath. In bared places, a red crumbly 

 soil is exposed ; and in one part a mass of rock, which 

 appeared to me, from its compact texture and the ab- 

 sence of stratification, to be porphyritic ; but I am not 

 Geologist sufficient to pronounce on such questions. 

 Mr. Wallace states that he found fragments of scoriae, 

 and believes the hill to be a volcanic cone. To the 

 south and east of this isolated peak, the elongated 

 ridges or table-topped hills attain a somewhat greater 

 elevation. 



The forest in the valley is limited to a tract a few 

 hundred yards in width on each side the different 

 streams : in places where these run along the bases of 

 the hills the hill-sides facing the water are also richly 

 wooded, although their opposite declivities are bare or 

 nearly so. The trees are lofty and of great variety ; 

 amongst them are colossal examples of the Brazil nut 

 tree (Bertholletia excelsa), and the Pikia. This latter 

 bears a large eatable fruit, curious in having a hollow 

 chamber between the pulp and the kernel, beset with 

 hard spines which produce serious wounds if they 

 enter the skin. The eatable part appeared to me not 

 much more palatable than a raw potato ; but the 

 inhabitants of Santarem are very fond of it, and 

 undertake the most toilsome journeys on foot to gather 

 a basketful. The tree which yields the tonka bean 



