If Passover is the type of the Mass (as Catholics would no doubt agree) then why would transubstantiation make sense typologically? Consider this: In the original Passover, we have 4 main elements- the bread, the wine, the flesh of the Lamb and the blood of the Lamb. From a Lutheran perspective, they correspond to the body (flesh of the Lamb) present in the bread. The blood is corresponds to the blood of Christ present in the wine. If you have transubstantiation, then you only have two of the elements and the typological connection is utterly destroyed. The elements of bread and wine go away, and therefore you are only left with blood and body with their connection to the type of the Passover Lamb. I think that this is an important point to make in this ongoing debate.