When I arrived home I looked up the story of Bodhidharma and Huiko in Zen Flesh, Zen Bones, the slender anthology of Zen stories and Zen koans compiled by Paul Reps. There the two stories of the teacher Bodhidharma and his disciple Huiko are combined into one. The postulant Huiko stands in the snow and offers his arm, his turmoil, and his question to the teacher Bodhidharma. But in Zen Flesh, Zen Bones the story is followed by this comment from the medieval monk Mumon:

“Bodhidharma remained years in China and had only one disciple and that one lost his arm and was deformed,” says Mumon.

“Alas," Momon concludes, "ever since he has had brainless disciples!”