, ▁but ▁that ▁root stock s ▁and ▁di as por es ▁might ▁have ▁been ▁buried ▁to ▁spr out ▁again . ▁Indeed , ▁this ▁possibility ▁cannot ▁be ▁ruled ▁out ▁completely ▁because ▁of ▁the ▁failure ▁of ▁the ▁Government ▁to ▁undert ake ▁any ▁research ▁immediately ▁after ▁the ▁ 1 8 8 3 ▁er u ption ▁of ▁Krak ato a . ▁Only ▁as ▁late ▁as ▁June ▁ 1 8 8 6 ▁the ▁first ▁bi ologist , ▁Mel ch ior ▁Tre ub , ▁came ▁to ▁take ▁stock , ▁but ▁grass es ▁had ▁already ▁been ▁observed ▁on ▁the ▁s lop es ▁in ▁ 1 8 8 4 ▁by ▁the ▁Dutch ▁ge ologist ▁Rog ier ▁Ver be ek ▁( 1 8 4 5 – 1 9 2 6 ). ▁ ▁Back ▁in ▁the ▁Netherlands ▁( 1 9 3 1 – 1 9 6 3 ) ▁ ▁In ▁ 1 9 3 1 ▁Back er ▁and ▁his ▁family ▁returned ▁to ▁the ▁Netherlands . ▁They ▁first ▁lived ▁in ▁H aar lem ▁and ▁then ▁settled ▁in ▁He em st ede ▁where ▁he ▁worked ▁until ▁his ▁last ▁years ▁on ▁his ▁‘ mag num ▁op us ’ , ▁the ▁Flora ▁of ▁Java . ▁Back er ▁made ▁Rein ier ▁Corn el is ▁Bak hu izen ▁van ▁den ▁Br ink ▁Jr . ▁( 1 9 1 1 – 1 9 8 7 ) ▁co - author ▁of ▁the ▁Flora ▁of ▁Java . ▁On ▁ 2 2 ▁February ▁ 1 9 6 3 ▁Corn el is ▁And ries ▁Back er ▁passed ▁away . The ▁Flora ▁of ▁Java ▁was