Frederic H. Sawyer, The Inhabitants of the Philippines
“ But not alone the Moro sword and spear has delayed for so long the conquest of Mindanao. Deadly fevers lurk in the lowlands, the swamps and the creeks of that rich and fertile island.The Moros appear impervious to the malaria. At all events they live and thrive in, or in close proximity to, mangrove swamp and flooded jungle. The Tagal or the Visaya is not immune, and some even resist an attack of the terrible perniciosa less than a white man. I shall never in my life forget the awful sights I witnessed in 1887 and 1892 when some native regiments returned to Manila from the war in Mindanao. ”
