Careful observations of the blood taken at frequent intervals have proved that the blood reflects the physiologic and pathologic processes of the human organism. Clinicians and surgeons are realizing this fact more and more and are utilizing examinations of the blood much more frequently than those who preceded them. The physician of yesterday, depending on the number of leukocytes and the percentage of polymorphonuclear neutrophils for his information in cases of severe infections, often found himself unable to explain apparently contradictory relationships. With the appearance of the work of Arneth and Schilling, this apparently false relationship was clarified and explained. Today, while the actual number of leukocytes is of but casual importance, the number of immature neutrophils or "staff cells" has achieved the center of the stage.
The importance of the staff cell in infections has been proved beyond doubt. Of what value is the careful morphologic examination of the