Who said, "'...we might as well begin t' look out fer ol' number one'"?

The Tattered Man said, "Look-a-here, pardner," he said, after a time. He regarded the corpse as he spoke. "He 's up an' gone, ain't 'e, an' we might as well begin t' look out fer ol' number one. This here thing is all over. He 's up an' gone, ain't 'e? An' he 's all right here. Nobody won't bother 'im. An' I must say I ain't enjoying any great health m'self these days."