Half the romantic spell of _Childe Roland_ lies in the wonderful suggestion of impending catastrophe. The gloom is alive with mysterious and impalpable menace; the encompassing presences which everything suggests and nothing betrays, grow more and more oppressively real, until the decisive moment when Roland's blast suddenly lets them loose. For the power that Browning rejoiced to imagine was pre-eminently sudden; an unforeseen cataclysm, abruptly changing the conditions it found, and sharply marking off the future from the past. The same bias of imagination which crowded his inner vision of space with abrupt angular forms tended to resolve the slow, continuous, organic energies of the world before his inner vision into explosion and catastrophe. His geology neglects the æons of gradual stratification; it is not the slow stupendous upheaval of continents, but the volcanic uprush of the molten ore among the rocks, which renew the ancient rapture of the Paracelsian God. He is the poet of the sudden surprises of plant-life: the bud "bursting unaware" into flower, the brushwood about the elm-tree breaking, some April morning, into tiny leaf, the rose-flesh mushroom born in a night. The "metamorphoses of plants,"[108] which fascinated Goethe by their inner continuity, arrest Browning by their outward abruptness: that the flower is implicit in the leaf was a fact of much less worth for him than that the bud suddenly passes into something so unlike it as the flower. The gradual coming on of spring among the mountains concentrates itself for him in one instant of epic sublimity,--that in which the mountain unlooses its year's load of sound, and "Fold on fold all at once it crowds thunderously down to his feet."[109] [Footnote 108: _Metamorphose der Pflanzen_.] [Footnote 109: _Saul_.] Even in the gradual ebb of day he discovers a pregnant instant in which day dies:-- "For note, when evening shuts, A certain moment cuts The deed off, calls the glory from the grey."