Resolutely he drew out his clasp knife and, stooping over the stricken man, he excised the protruding bud, cutting as close to the scalp as he could with safety. The thing was unnaturally tough and rubbery; it exuded a thin, sanguinous fluid; and he shuddered when he saw its internal structure, full of nerve-like filaments, with a core that suggested cartilage.