 Each cost about 300 livres to construct, usually out of fabric, leather, and stuffing, and occasionally including actual human bones to form the torso.Various strings and straps serve to simulate the stretching of the birth canal and perineum to demonstrate the process of childbirth.The head of the infant mannequin has a shaped nose, stitched ears, hair drawn with ink, and an open mouth (with tongue) into which a finger can be inserted to a depth of .