R. H. Boll's Lessons on Mark has been compiled from the International Sunday School Lessons for first two quarters for 1918. They were first published in The Word and Work as follows:

      First Lord's Day Lesson of January. Lesson 1. January 6, 1918. John Prepares the Way for Jesus (Mark 1:1-11). The Word and Work 10 (December 1917): 515-516.
      Second Lord's Day Lesson of January. Lesson 2. January 13, 1918. Jesus Begins His Work (Mark 1:12-20). The Word and Work 11 (January 1918): 28-29.
      Third Lord's Day Lesson of January. Lesson 3. January 20, 1918. Jesus at Work (Mark 1:21-34). The Word and Work 11 (January 1918): 30-31.
      Fourth Lord's Day Lesson of January. Lesson 4. January 27, 1918. Jesus Forgiving Sins (Mark 2:1-12). The Word and Work 11 (January 1918): 32-33.
      First Lord's Day Lesson of February. Lesson 5. February 3, 1918. Jesus Lord of the Sabbath (Mark 2:23-3:5). The Word and Work 11 (January 1918): 34-35.
      First Lord's Day Lesson of February. Lesson 5. February 3, 1918. Jesus Lord of the Sabbath (Mark 2:23-3:5). The Word and Work 11 (February 1918): 70-71. (Duplicated.)
      Second Lord's Day Lesson of February. Lesson 6. February 10, 1918. Jesus Chooses the Twelve (Mark 3:7-19a). The Word and Work 11 (February 1918): 72-73.
      Third Lord's Day Lesson of February. Lesson 7. February 17, 1918. Jesus Teaching by Parables: Four Kinds of Ground (Mark 4:1-8, 14-20). The Word and Work 11 (February 1918): 74-75.
      Fourth Lord's Day Lesson of February. Lesson 8. February 24, 1918. Jesus Teaching by Parables: The Growth of the Kingdom (Mark 4:21-34). The Word and Work 11 (February 1918): 76-77.
      First Lord's Day Lesson of March. Lesson 9. March 3, 1918. Jesus Bringing Peace (Mark 4:35-41; 5:15-20). The Word and Work 11 (March 1918): 112-113.
      Second Lord's Day Lesson of March. Lesson 10. March 10, 1918. Jesus Restoring Life and Health (Mark 5:21-23, 35-43). The Word and Work 11 (March 1918): 114-115.
      Third Lord's Day Lesson of March. Lesson 11. March 17, 1918. Jesus Sending Forth the Twelve (Mark 6:7-13, 30). The Word and Work 11 (March 1918): 116-117.
      Fourth Lord's Day Lesson of March. Lesson 12. March 24, 1918. Jesus Ministering to the Multitude (Mark 6:32-44). The Word and Work 11 (March 1918): 118.
      Fourth Lord's Day Lesson of March. Lesson 13. March 31, 1918. Jesus Our Example in Service (Review). The Word and Work 11 (March 1918): 119.

      First Lord's Day Lesson of April. Lesson 1. April 7, 1918. Jesus Sets Men Free (Mark 7:24-35). The Word and Work 11 (April 1918): 156-157.
      Second Lord's Day Lesson of April. Lesson 2. April 14, 1918. Jesus Requires Confession and Loyalty (Mark 8:27-38). The Word and Work 11 (April 1918): 158-159.
      Third Lord's Day Lesson of April. Lesson 3. April 21, 1918. Jesus Transfigured (Mark 9:2-10). The Word and Work 11 (April 1918): 160-161.
      Fourth Lord's Day Lesson of April. Lesson 4. April 28, 1918. Jesus Rebukes Selfishness (Mark 9:33-42). The Word and Work 11 (April 1918): 162-163.
      First Lord's Day Lesson of May. Lesson 5. May 5, 1918. Jesus Sets New Standards of Living (Mark 10:17-27). The Word and Work 11 (May 1918): 191-192.
      Second Lord's Day Lesson of May. Lesson 6. May 12, 1918. Jesus Faces the Cross (Mark 10:32-45). The Word and Work 11 (May 1918): 193-194.
      Third Lord's Day Lesson of May. Lesson 7. May 19, 1918. Jesus Exercising Kingly Authority (Mark 11:15-18, 27-33). The Word and Work 11 (May 1918): 195-196.
      Fourth Lord's Day Lesson of May. Lesson 8. May 26, 1918. Jesus Silences Adversaries (Mark 12:28-34, 41-44). The Word and Work 11 (May 1918): 197-198.
      First Lord's Day Lesson of June. Lesson 9. June 2, 1918. Jesus Gratefully Accepts Unselfish Service (Mark 14:1-9). The Word and Work 11 (June 1918): 222-223.
      Second Lord's Day Lesson of June. Lesson 10. June 9, 1918. Jesus Faces Betrayal and Denial (Mark 14:17-26). The Word and Work 11 (June 1918): 224-225.
      Third Lord's Day Lesson of June. Lesson 11. June 16, 1918. Jesus on the Cross (Mark 15:22-39). The Word and Work 11 (June 1918): 226-227.
      Fourth Lord's Day Lesson of June. Lesson 12. June 23, 1918. Jesus Triumphs over Death (Mark 16:1-11). The Word and Work 11 (June 1918): 228-229.
      Fifth Lord's Day Lesson of June. Lesson 13. June 30, 1918. Review of the Twelve Lessons. The Word and Work 11 (June 1918): 229.