Although the Matis often use bows an arrows, they specialize in the blowgun hunting.  Their blowguns are four meter precision instruments and are both beautiful and functional.  Note the monkey mandible attached to the quiver containing darts with curare poison.   The monkey mandible serves as a reservoir of mud that is used as ballast and applied to the tip of the dart.  Additionally, notice the dart he is holding in his mouth that has two pieces of kapoc cotton.  Other Amazonian natives, such as the Korubo tribe, only used one piece of cotton and thicker, heavier darts.