If a neckbone of person were person - in parallel to the bird's neck the other day - the question arises as to whether or when the status of impurity kicks in. With the example of Eli the high priest of the Book of Samuel (I), who fell, whose neckbone broke, and who died, "because he was old." Also, a beraita on the melikah of a bird burnt-offering. And how it's different from a burnt-offering bird's melikah. With physical directions, in its intricacy.