Eliot accepted the suggestion , made in 1935, that this line (76) was derived from "Non sum qualis eram" ("I am not now as once I was"), the best-known poem by Ernest Dowson (1867-1900), in which the phrase
"There falls thy shadow" (and variants) is repeated. Eliot commented that "This derivation had not occurred to my mind, but I believe it to be correct because the lines . . .have always run in my head."
Shadows, literal and figurative, always symbolic, are cast throughout the HEART OF DARKNESS. The boat on which Marlow travels upstream to Kurtz moves in shadows, once in a fog, through which is heard a cry "as of infinite desolation" (p. 66 in Bantam; p. 110 in Signet Classics edition) which turns into a shrieking but whose source and meaning they never know; Kurtz dies in shadow (see pages 117-118 in Bantam; pages 147-148 in Signet Classics); "pain" is a shadow, feeding on Kurtz like a beast
"satiated and calm" (pages 102 and 136, respectively); Marlow's knowledge of Kurtz's involvement with savage rites and ceremonies is a
"nightmare secret," a "shadow" which he keeps to himself, to deal with alone (cf. pages 105-109 and 138-141, respectively); Kurtz himself