THE ISLANDS AND THEIR POPULATION 63 
six thousand. As might be expected under these condi- 
tions, they are ruder in their habits than almost all the 
other heathens. 
Pagans of Mindanao. In Mindanao the pagan 
people are cut into two masses by the intrusive Moros 
of Lake Lanao. The smaller western section is inhabited 
by the Subanun or “‘ River People,’ some thirty thou- 
sand in number. East of Lake Lanao, in fact stretching 
down to the narrow strip of eastern coast colonized by 
the Bisaya, are two large groups, the Bukidnon, esti- 
mated to number nearly fifty thousand, and the Manobo 
-in the valley of the Agusan, about forty thousand 
strong. On the headwaters of the Agusan lives a small 
and almost unknown tribe, the Manguangan. South 
of them, on the peninsula east of the Gulf of Davao, 
are a better-known group, the Mandaya. North and 
west of the Gulf in the interior are the Ata, and nearer 
the coast, the Bagobo. The latter are the Mindanao 
tribe on whom there is fullest information. To the 
south, in the Sarangani Peninsula, there live three 
tribes, the Bilaan, highest in the mountains; next, the 
Tagakaolo; and below them, the Kulaman; while 
Moros are settled on the immediate coast. On the map, 
these groups create a striking impression of a stratifica- 
tion of population. It is possible that when the distribu- 
tion of these four nationalities has been worked out more 
in detail, it will prove to be less regular in its arrange- 
ment of concentric bands. It is doubtful how far the 
position of these people represents actual successive 
immigrations, or on the other hand a mere infiltration 
of alien customs from the seaboard. 
Somewhat to the west of the last groups, and sepa- 
rated from them by Moros or by uninhabited tracts, 
are the Tirurai. Their affiliations seem to be with the 
eastern tribes rather than with the Subanun. Like 

