COLLECTING EXPEDITION TO BATANG PADANG, 133 
At about 8 A. M. on the 1gth I left the camp with HARISON, 
the “boy’”’ and 18 Sakais, and reached Kuala Woh at 2 P. M. 
The Sakais were too tired to go on any farther that day, and so 
I forded the Woh and went with the ‘‘boy”’ only to Breumen, 
and after much trouble got a boat and reached Tapa at 7 P. M. 
The exposures of rock along the banks of the Batang Padang 
River from Kuala Woh to Tapa are all, asfar as I saw, of the 
ancient stratified series. The beds are much twisted, contort- 
ed and upheaved, in places the strata being nearly vertical. 
Overlying these rocks are usually thick beds of river sands, 
similar to that on which the village of Tapa stands. In places 
these beds rise to 30 feet above the level of the river. 
The rock exposures on the Woh are all apparently granitic. 
The granite there and on Gunong Batu Puteh from base to 
extreme summit is a coarse grained rock, with large white 
felspar crystals and largely mixed with dull blue quartz. The 
sand in the streams derived from this rock is very characteristic, 
being quite blueish in appearance. ‘The subsoil formed by its 
decomposition is also much redder than that formed by the 
granite of the Larut hills. The surface soil both there and in 
other parts of Perak seems to depend, in a great measure, as 
regards its vegetable constituents or humus, on the presence 
or absence of white ants (¢ermztes). When the height at which 
these insects cease to thrive is passed on the hills, a very mark- 
ed difference in the colour and depth of the surface soil is notice- 
able, and the same thing is to be seen in the low country in 
swampy land which is unsuited to their existence. 
That the soil is really any poorer for its loss of vegetable 
matter is not at all certain, for the inorganic constituents of 
the humus are still present, though they have been altered by 
passing through an animal organism. This may account for 
the fertility of some of the apparently very poor soils to be 
seen in some parts of the State. 
Nothing particular happened during the walk down from 
Gunong Batu Puteh beyond the usual experiences of a long 
jungle tramp, except that near Kuala Woh I saw in the middle 
of the track just in front of me the head of a black cobra look- 
ing out from.under a root; a knock on the neck with my walk- 
ing stick rendering it powerless. I got it out of its hole, and 
