This study discusses the handling and use of blood at Greek sacrifices as depicted in Greek vase-painting. Modern scholars have usually assumed that the blood from the animal victims was completely discarded by pouring it on or at the altar, since the blood belonged to the divine part of the sacrifice. However, a more comprehensive analysis of the literary and epigraphical evidence shows that it is more likely that the blood at regular thysia sacrifices was kept and eaten by the human worshippers.
The analysis of the iconographical evidence can be taken to further support the suggestion that the blood at Greek animal sacrifices was usually collected, in order to be prepared as food, after a small quantity had been sprinkled on the altar. The main support for this proposal is how and when blood is shown or referred to on the vases, and when it is not. Blood pouring out of the victim is never part of the iconography of thysia but instead confined to representations of sacrifices, at which the blood had to be discarded, or set in a mythical context and with little or no correspondence to actual, practised rituals. The sphageion, the vessel used for collecting the blood, most frequently occurs in scenes showing the mageiros cutting up the meat, indicating the use of this vessel when preparing the blood for consumption. The bloodstains on the altar, finally, are not found on all altars and, when depicted, there are only a few stains on the vertical side of the altar, and the altars are never shown as covered with blood.
Our knowledge of the normative practice of Greek animal sacrifice is usually based on the written and iconographical sources. Recent publications of animal bones from Greek sanctuaries offer new possibilities to define the practical execution of sacrificial rituals. This paper discusses the god's part of the animal victim burnt on the altar, which could consist of the thigh bones or the osphys (sacrum and caudal vertebrae) or both. The altar debris and consumption refuse from ritual contexts allow us to distinguish variations within this norm. Sheep and goat femora were the preferred parts to burn, though at some sites cattle thigh bones were favoured. Tails and sacrum bones are rarely found. Pig bones hardly ever seem to have formed part of the god's share burnt on the altar, though pigs clearly were eaten in sanctuaries. It is suggested that the thigh bones may have been the original offering at a thysia, perhaps a tradition deriving from the Mycenaean period. The burning of the tails could have been inspired from Near eastern sacrificial practices and was perhaps added to the Greek animal sacrifices at a later stage to increase the element of divination.