Fig. 2.

A schematic diagram of a lizard heart showing correct placement of the perfusion needle. Prior to needle insertion, incisions are made into the ventricle (step 4.7) and right atrium (step 4.8). The perfusion needle is then inserted though the incision in the ventricle into the right aorta (step 4.9). The tip of the perfusion needle is visible in the right aorta below the branch point of the right systemic artery.