The book: An Illustrated Dictionary of the Gods and Symbols of Ancient Mexico and the Maya.
Miller, Mary and Karl Taube,  1993: Thames & Hudson, Ltd, London.
ISBN 0-500-27928-4.

The excerpt: Bloodletting

The act of drawing blood from the human body was practiced routinely throughout Mesoamerica for ritual purposes. Because the gods had shed their own blood to create humanity, human blood was the single most important offering that could be made in return. In this state of blood "debt," captives of battle were taken alive, their blood shed later in temples and shrines to honor the pact with the gods. The nobles, and perhaps all people, performed auto sacrifice.

Jade versions of the sharp spines from the stingray survive from the Olmec times, indicating that during the first millennium BC Mesoamerican peoples were familiar with the serrated bony spine that arms the tail of this sea creature. Because of the acute angle of the serrations, once a stingray spine has pierced the skin it cannot be removed without causing painful damage: It is easier in fact to pull the spine completely through a perforation. The Maya buried their noble male dead with stingray spines --perhaps in pouches long decayed -- over the groin, and these spines were the perforators used to draw blood from the penis.

The Maya also pierced the flesh with obsidian blood letters and carved bones. They collected the dripping blood on strips of paper, which they then placed in broad, flat-bottomed bowls and set afire. The implements, as well as the bowls, were frequently prized funerary offerings; nobles wrapped bloodletting equipment in their sacred bundles. Yaxchilan women often wore headdresses like those of warriors when undergoing auto sacrifice and it was not uncommon for men to adopt the mutilated, shredded attire of captives, as if identifying their own bloodletting with that of sacrificial victims.

Captives themselves may have been forced to perform auto sacrifice; some bear the necessary spines and paper in ancient depictions. In other cases, victors forcibly drew the blood of captives, as shown in the Bonampak murals, where warriors pull out the fingernails of their prisoners.

Maya blood letters and other things associated with bloodletting often bear the triple "bow tie," probably a representation of knotted paper. The motif turns up at Tula and Tenochtitlan, where it is featured on the body of the Xiucoatl linking it to blood and sacrifice.

Most Central Mexican peoples used the spines of the maguey plants to draw blood, and to keep these spines sharp and at hand they stored them in a ball of twisted grass, much as a seamstress keeps her needles and pins in a cushion. The grass ball with spines became an important symbol of Aztec nobility, indicating both their privilege and their responsibility to let blood. In Aztec representations of bloodletting, lords and gods draw blood from the ear, shin, knee, and elbow.

An Illustrated Dictionary of the Gods and Symbols of Ancient Mexico and the Maya.
Miller, Mary and Karl Taube,  1993: Thames & Hudson, Ltd, London.
ISBN 0-500-27928-4.