Read it through once

Dr. Hockin gave us a ghastly curiosity—a lignified caterpillar with a plant growing out of the back of its neck—a plant with a slender stem 4 inches high. It happened not by accident, but by design—Nature's design. This caterpillar was in the act of loyally carrying out a law inflicted upon him by Nature—a law purposely inflicted upon him to get him into trouble—a law which was a trap; in pursuance of this law he made the proper preparations for turning himself into a night-moth; that is to say, he dug a little trench, a little grave, and then stretched himself out in it on his stomach and partially buried himself—then Nature was ready for him. She blew the spores of a peculiar fungus through the air with a purpose. Some of them fell into a crease in the back of the caterpillar's neck, and began to sprout and grow—for there was soil there—he had not washed his neck. The roots forced themselves down into the worm's person, and rearward along through its body, sucking up the creature's juices for sap; the worm slowly died, and turned to wood. And here he was now, a wooden caterpillar, with every detail of his former physique delicately and exactly preserved and perpetuated, and with that stem standing up out of him for his monument—monument commemorative of his own loyalty and of Nature's unfair return for it.