33^ VERY THICK BAMBOOS. 



the valley, which from above seemed quite smooth, we dis- 

 covered to be intersected and furrowed by great numbers 

 of deep-cut streams. Looking back from below, the 

 descent appears as the edge of a table-land, with numerous 

 indented dells and spurs jutting out all along, giving it a 

 serrated appearance. Both the top and sides of the sierra 

 are covered with trees, but large patches of the more 

 perpendicular parts are bare, and exhibit the red soil, 

 which is general over the region we have now entered. 



The hollow affords a section of this part of the country ; 

 and we find that the uppermost stratum is the ferruginous 

 conglomerate already mentioned. The matrix is rust of 

 iron (or hydrous peroxide of iron and hsematite), and in 

 it are embedded water-worn pebbles of sandstone and 

 quartz. As this is the rock underlying the soil of a large 

 part of Londa, its formation must nave preceded the 

 work of denudation by an arm of the sea, which washed 

 away the enormous mass of matter required before the 

 valley of Cassange could assume its present form. The 

 strata under the conglomerate are all of red clay shale of 

 different degrees of hardness, the most indurated being at 

 the bottom. This red clay shale is named " keele " in 

 Scotland, and has always been considered as an indication 

 of gold ; but the only thing we discovered was, that it 

 had given rise to a very slippery clay soil, so different 

 from that which we had just left, that Mashauana, who 

 always prided himself on being an adept at balancing 

 himself in the canoe on water, and so sure of foot on land 

 that he could afford to express contempt for any one less 

 gifted, came down in a very sudden and imdignified 

 manner, to the delight of all whom he had previously 

 scolded for falling. 



Here we met with the bamboo as thick as a man's 

 arm, and many new trees. Others, which we had lost sight 

 of since leaving Shinte, now re- appeared ; but nothing 

 struck us more than the comparative scragginess of the 

 trees in this hollow. Those on the high lands we had 

 left were tall and straight ; here they were stunted, and 

 not by any means so closely planted together. The only 

 way I could account for this was by supposing, as the trees 

 were of different species, that the greater altitude suited 

 the nature of those above, better than the lower altitude 

 did the other species below. 



Sunday, 2nd April. — We rested beside a small stream, 



