▁In ▁ 1 9 7 9 , ▁they ▁tra ve led ▁studying ▁the ▁concept ▁of ▁tour ism ▁as ▁pil gr image . ▁Tow les ▁critic ised ▁Turn b ull ' s ▁semi - aut obi ographical ▁work ▁The ▁Human ▁Cy cle ▁( 1 9 8 3 ), ▁which ▁omitted ▁all ▁references ▁to ▁their ▁relationship . ▁ ▁Turn b ull ▁arranged ▁for ▁Tow les ' ▁research ▁to ▁be ▁published ▁post hum ously . ▁It ▁appeared ▁in ▁ 1 9 9 3 ▁as ▁N k umb i ▁init iation ▁rit ual ▁and ▁structure ▁among ▁the ▁M bo ▁of ▁Za ï re ▁and ▁as ▁As a : ▁M yth ▁of ▁Origin ▁of ▁the ▁Blood ▁Bro ther hood ▁Among ▁the ▁M bo ▁of ▁the ▁It uri ▁Forest , ▁both ▁in ▁Ann ales ▁of ▁the ▁Royal ▁Museum ▁for ▁Central ▁Africa ▁( T erv uren , ▁Belg ium ), ▁vol . ▁ 1 3 7 . ▁ ▁Later ▁years ▁Late ▁in ▁life ▁Turn b ull ▁took ▁up ▁the ▁political ▁cause ▁of ▁death ▁row ▁in m ates . ▁After ▁his ▁partner ' s ▁death , ▁Turn b ull ▁don ated ▁all ▁his ▁belong ings ▁to ▁the ▁United ▁Neg ro ▁College ▁Fund . ▁He ▁don ated ▁all ▁their ▁research ▁materials , ▁most ▁of ▁which ▁were ▁the ▁product ▁of ▁his ▁career , ▁to ▁the ▁College ▁of ▁Char l eston , ▁ins isting ▁that ▁the ▁collection ▁be ▁known ▁under ▁Tow les ' ▁name ▁alone . ▁ ▁In ▁ 1 9 8 9 , ▁Turn b ull ▁moved ▁to ▁Blo om ington , ▁Indiana