21G BOTANICAL INFORMATION. 



curacy of these statements, as proceeding from an individual 

 who saw a comparatively small portion of the country whose 

 general features he has thus sketched, I may mention that 

 much of my information was derived from the Vagiieiros or 

 herdsmen, who drive tlie cattle from Piauhy to the capital of 

 Pernambuco, and who travel through various parts of the 

 country. I am much indebted to the observations which 

 were kindly communicated to me by Captain Matlias J. da 

 Silva Pereira, who is an architect at Oeiras, and who, in his 

 journeys in almost every district of these provinces, has ac- 

 quired great knowledge of their geographical features. 



The Serra dos dois Irmaos consists of a solid, whitish, 

 coarse-grained granite, in which mica commonly appears in 

 silvery-white large laminae, and mingled with layers of a 

 blackish-grey, and greyish-blue colour. As we proceeded 

 onward, we had hoped to see a very marked change of vege- 

 tation ; but our expectations were not fulfiiled, though we 

 noticed an alteration in the geological features of the country, 

 and observed in many places a strong clayey earth, frequent- 

 ly of a brick-red colour, looking as if it had been burnt, and 

 mixed with fragments of quartz. These lumps of earth were 

 like stones; and, when broken, appeared cloudy-coloured, 

 and full of holes. Our guide assured us, that such stones, 

 which are called at Goyaz Batatas^ were there considered as 

 undoubted indications of the existence of gold ; and, that 

 even here, this metal, although in small quantities, is still 

 occasionally washed up. 



Behind the ridge of dois Irmaos, we saw another hill, appa- 

 rently belonging to the same range, and we skirted it, in order 

 to descend lower down the Catingas to tlie Fazenda Serrinha, 

 where we bivouacked beneath a large and densely foliaged Joa- 



\Xr 1 . JO 



tree. VV e had just gone cheerfully to rest, when distant thun- 

 der awakened us ; and instead of the bright firmament, glit- 

 termg with the lustre of unnumbered stars, which had, as it 

 were, lighted us to bed, we found ourselves enveloped in the 

 thickest darkness. The occasional flashes of lightning re- 

 vealed the agitation of the skv, and illuminated the margins 



