 The profile of the wooden model is more ovoid than that of the engravings, but less so than the finished product.It has been suggested that Michelangelo on his death bed reverted to the more pointed shape.However, Lees-Milne cites Giacomo della Porta as taking full responsibility for the change and as indicating to Pope Sixtus that Michelangelo was lacking in the scientific understanding of which he himself was capable.