The very first time he looked down the barrel of a microscope, Lister marveled at the intricate world that had previously been hidden from his sight. He delighted in the fact that the objects he could observe under the magnifying lens were seemingly infinite. Once, he plucked a shrimp from the sea and watched in awe at “the heart beating very rapidly” and “the aorta pulsating.” He noticed how the blood slowly circulated through the surface of the limbs and over the back of the heart as the creature wriggled under his gaze.
