From where he swung lightly against his oars he looked down into the water and saw the tiny fish that were coloured like the trailing filaments and swam between them and under the small shade the bubble made as it drifted. They were immune to its poison. But men were not and when some of the filaments would catch on a line and rest there slimy and purple while the old man was working a fish, he would have welts and sores on his arms and hands of the sort that poison ivy or poison oak can give. But these poisonings from the agua mala came quickly and struck like a whiplash.