/9 BRITISH BORNEO. 
a sudden the whole detachment dashes off in the direction of 
the sea, towards the mangrove swamps and the zzpas. Some- 
times these detached colonies reverse the direction of their 
revolutions after leaving the main body, and, instead of from 
left to right, revolve from right to leit:. Some of themmeonas 
tinue for a long time revolving in a circle, and attain a great 
height before darting off in quest of food, while others make 
up their minds more expeditiously, after a few revolutions. 
Amongst the bats, three white ones were, on the occasion of 
my visit, very conspicuous, and our followers styled them the 
Raja, his wife and child. Hawks and sea-eagles are quickly 
attracted to the spot, but only hover on the outskirts of the 
revolving coil, occasionally snapping up a prize. I also noticed 
several hornbil Is, but they appeared to have been only attracted 
by curiosity. Mr. BAMPFYLDE informed me that, on a previ- 
ous visit, he had seen a large green snake settled on an over- 
hanging branch near which the bats passed and that ecca- 
sionally he managed to secure a victim. I timed the bats 
and found that they took almost exactly fifty minutes to 
come out of the caves, a thick stream of them issuing all that 
time and at a great pace, and the reader can endeavour to 
form for himself some idea of their vast numbers. They had 
all got out by ten minutes to six in the evening, and at about 
six o'clock the swifts began to come home to. roost. They 
came in in detached, independent parties, and I found it im- 
possible to time them, as some of them kept very late hours. 
I sleptin the Simud Putih cave on this occasion, and found: hat 
next morning the bats returned about 5 A.M., and that he 
swifts went out an hour afterwards. 
As shewing the mode of formation of these caves, I may 
add that I noticed, imbedded in a boulder of rock in the upper 
caves, two pieces of coral and several fossil marine shells, 
bivalves and others. : 
The noise made by the bats going out for their evening 
promenade resembled a combination of that of the surf break- 
ing on a distant shore and of steam being gently blown off 
from a vessel which has just come to anchor. 
There are other interesting series of caves, and one— 
that of Madai, in Darvel Bay on the East coast—was 
