( 529 ) 



ovorywlioi-o old slate lavci-s (mhiio lo \\\r surracc. Only Ikmv idkI tliofo 

 yoiiimiM' foniialioiis, specially lVe(>-sl(>iie, coxcn- (lie oNlei-. 



IC we now lake ijilo coiisideralioii thai only in die lasl 'M) xcars 

 eidier \\\o Haliaiis on the L'|>por-Maliakaiii oi- die Keiijas mi the 

 r|)|)ef-Kajan Iia\"e come into snch close conlaci widi hiulier ci\ili/-e(l 

 nations that it induced sonic of llioir men to iiiidei'lak(> commercial 

 enterprises lor llie pnrchasinu' of sail and linen. 1 think that lamjnslilied 

 in assei'tinu' that the two uronps of tribes nnder consideration heloni; 

 to the same race, that they liax'e livcil for nj)wards of a linndre<l 

 years iji c<»nn(ries with a ditlerent climate, that they liaxe had hut 

 little mutual intercourse and have not mixed: that they have not 

 chan.ued their life as cultixators of the soil and liaxe (lexelo|)ed 

 x\ itliout external influences. 



What ellect this ditrerence of climale can liaxe on the popii- 

 latioji, may he derixed from the fact, that in my o|)inion the thin- 

 ness of the population in Uorneo depends in the lirsi place on the 

 iidlnences of the climate, and much more on the customs of the 

 people than on the iidectious diseases, such as cholera, smallpox, which 

 are introduced from the coast. As both I p[>er-Kajan and I'pper- 

 Mahakam ai"e so difticult to reach that infectious diseases hut xeiT 

 seldom extend to them, we liaxe, when tryini^ to delermine xxlial 

 the restdt of those changed conditions of life is for the Indians, only 

 to deal xx'itli those factors which are sometimes comprised under the 

 name of intluences of the climate. 



What is understood by influences of (he climate in (he hiuhlands 

 of I)orneo became clear to me for the first time in the sultanate 

 of Sambas on the West coast of (he islajid, xx here I xxas s(ruck 

 by (he ditrerencc in the sprea<l of malaria among (he jK)[)nlation 

 of (he marshy coas( regions and that of (Ik^ highlands. In oi(1(M' (o 

 ge( a fuller knowledge of (his ditlertMice, 1 made an iiKpiiry in(o 

 the ti'aces of malaria infec(ion on abont 3000 children, both in the 

 marshy allnxial jilaiii and in the highlands. These children had not 

 been offered (o me on purpose for (his inx-estiga(ion, bu( for an iinpiiry 

 iii(o (he residts of (he xaccinalion among (he Malay an<l Dajak 

 ])ojMdation. 



Among the j)opula(ioii of (he allnxial plains 1 found among 2J03 

 children t»iily (i xxidi a chronic hard splenic (iimor. or 2,8 per 1000. 



Among 420 children of (he iijilands i( occurred in 403 children, 

 or 1)511.5 per 1000. 



The i-emainiiiLi MIMJ children origina(ed from I'egions, xxliich in 

 their htriiiatioii xxcre (he transition betxxeen the allnx'ial plains and 

 the uplan<l>. .l;iiius. I)eii\iènie Annce KSJIcS. 



36* 



