At dusk, Harry insisted on setting up the substage lamp which had been bought with the microscope, and by whose light he could go on looking until his bedtime, when his father helped him arrange a wick to feed the little glass-covered well in the slide so it would not dry up before morning. It was unwillingly, and only after his mother’s strenuous complaints, that the boy went to bed at ten o’clock. In the following days his interest became more and more intense. He spent long hours, almost without moving, watching the rotifers. For the little animals had become the sole object which he desired to study under the microscope, and even his father found it difficult to understand such an enthusiasm. During the long hours at the office to which he commuted, Henry Chatham often found the vision of his son, absorbed with the invisible world that the microscope had opened to him, coming between him and the columns in the ledgers. And sometimes, too, he envisioned the dim green water-garden where the little things swam to and fro, and a strangeness filled his thoughts. On Wednesday evening, he glanced at the fish bowl and noticed that the water beetle, the whirligig beetle, was missing. Casually, he asked his son about it. "I had to get rid of him," said the boy with a trace of uneasiness in his manner. "I took him out and squashed him." "Why did you have to do that?" "He was eating the rotifers and their eggs," said Harry, with what seemed to be a touch of remembered anger at the beetle. He glanced toward his work-table, where three or four well-slides with small green pools under their glass covers now rested in addition to the one that was under the microscope. "How did you find out he was eating them?" inquired Mr. Chatham, feeling a warmth of pride at the thought that Harry had discovered such a scientific fact for himself. The boy hesitated oddly. "I—I looked it up in the book," he answered. His father masked his faint disappointment. "That’s fine," he said. "I guess you find out more about them all the time." "Uh-huh," admitted Harry, turning back to his table. There was undoubtedly something a little strange about Harry’s manner; and now Mr. Chatham realized that it had been two days since Harry had asked him to "Quick, take a look!" at the newest wonder he had discovered. With this thought teasing at his mind, the father walked casually over to the table where his son sat hunched and, looking down at the litter of slides and papers—some of which were covered with figures and scribblings of which he could make nothing. He said diffidently, "How about a look?" Harry glanced up as if startled. He was silent a moment; then he slid reluctantly from his chair and said, "All right." Mr. Chatham sat down and bent over the microscope. Puzzled and a little hurt, he twirled the focusing vernier and peered into the eyepiece, looking down once more into the green water world of the rotifers. ————