Valley of the Black River. a7 
ness of the climate, and the violence of the winds 
that prevail in summer, the new imported vegeta- 
tion has proved but a sorry substitute for the old 
and vanished. It does not grow large enough to 
retain the scanty moisture, it is too short-lived, 
and the frail quickly-perishing rootlets do not 
bind the earth together, like the tough fibrous 
blanket formed by the old grasses. The heat 
burns it to dust and ashes, the wind blows it away, 
blade and root, and the surface soil with it, in 
many places disclosing the yellow underlying sand 
with all that was buried in it of old. For the 
results of this stripping of the surface has been 
that the sites of numberless villages of the former 
inhabitants of the valley have been brought to 
light. I have visited a dozen such village sites in 
the course of one hour’s walk, so numerous were 
they. Where the village had been a populous one, 
or inhabited for a long period, the ground was a 
perfect bed of chipped stones, and among these 
fragments were found arrow-heads, flint knives 
and scrapers, mortars and pestles, large round 
stones with a groove in the middle, pieces of hard 
polished stone used as anvils, perforated shells, 
fragments of pottery, and bones of animals. My 
host remarked one day that the valley that. year 
had produced nothing but a plentiful crop of arrow- 
heads. The anthropologist could not have wished 
for a more favourable year or for a better crop. I 
collected a large number of these objects; and 
some three or four hundred arrow-heads which I 
