I have indicated the locations of the different tribes in Dutch Borneo,
based on information gathered from official and private sources and on my
own observations.

I usually had a taxidermist, first a trained Sarawak Dayak, later a
Javanese, to collect mammals and birds. Fishes and reptiles were also
preserved in alcohol.

Specimens of ethnological interest were collected from the different
tribes visited; the collection from the Penihings I believe is complete.
Measurements of 227 individuals were taken and as soon as practicable will
be worked out by Doctor K.S. Schreiner, professor at the University of
Christiania. Vocabularies were collected from most of the tribes. In spite
of adverse conditions, due to climate and the limitations under which I
travelled, a satisfactory collection of photographic plates and films was
brought back. With few exceptions, these photographs were taken by myself.
For the pictures facing page 26 I am indebted to Doctor J.C.
Koningsberger, President of the Volksraad, Buitenzorg, Java. Those facing
pages 16 and 17 were taken by Mr. J.F. Labohm. The lower picture facing
page 286 was taken by Mr. A.M. Erskine.

My observations on the tribes are recorded in conformity with my itinerary,
and include the Kayans, Kenyahs, Murungs, Penyahbongs, Saputans, the
nomadic Punans and Bukits, Penihings, Oma-Sulings, Long-Glats, Katingans,
Duhoi (Ot-Danums), and the Tamoans. On one or two occasions when gathering
intelligence from natives I was very fortunate in my informants--an
advantage which will be appreciated by any one who has undertaken a similar
errand and has enjoyed the keen satisfaction experienced when drawing the
veil from primitive thought which lies so near and yet so far away.