He had received on his body the violent impact of the mass of earth pushed laterally from the crater excavated by the bursting of the shell. Accordingly his vertebral column was forcibly flexed, its ligaments were stretched, and hemorrhages were produced in the great muscles of the back. As the twelfth thoracic vertebra is the weakest spot in the spine, the roots of the cauda equina opposite this weak spot were probably injured. Such accidents are met in mines. The legs were powerless and numb. There was nausea, no vomiting, no gas, no dizziness or trouble in the head, not even pain in the small of the back. The accident had occurred at 8 A.M. Upon nightfall, he was removed on a stretcher to the field hospital, arriving at the base hospital four days later; and on the fifth day power began to return to the legs. Knees, ankles, and toes would move slightly November 6, though passive movements of the legs caused pain in the back. The deep reflexes were weak, the plantar reflexes flexor. The left cremasteric reflex was weaker than the right. Impairment of sensation was slight in both extremities, but the left leg was a little more numb than the right. The left lower abdominal reflex was lost. A band of hyperalgesia corresponded with the left eleventh and twelfth thoracic segments November 12, slight reflex disorders and some degree of paresis of the legs. Shell explosion: Paraplegia; sensory symptoms. =Case 238.= (HURST, January, 1915.) A lieutenant, 23, came to the ambulance September 15, 1914, having the morning before been to the firing-line with his company and thrown to the ground on his back by the explosion of a shell which he had seen falling behind him. He had not lost consciousness, but was unable to rise. After a night in the relief post, he was brought by automobile 12 kilometers to the ambulance. He complained of pain in the back, though no wound or ecchymosis could be found there, nor any painfulness of spinous processes or irregularity of bone. He had not emptied the bladder from the time of the shock. Preparations were made to catheterize on the morning of the 16th, when the patient after effort became able to micturate. There was crural paraplegia such that he could not sit or walk even when supported. Lying down, he could move his legs slightly sidewise. Anesthesia to pin-prick and temperature was complete to the groin; but tactile anesthesia was found only in the sacral root territory, namely in the feet, the outer aspect of the legs, the posterior surface of the thighs, and the scrotum. There was loss of sense of position for the toes. The plantar reflexes were abolished; but there were no other reflex disorders; nor was there any evidence of other disorder. September 20, the man was evacuated by sanitary train in the same status as at entry. January 27, 1915, the patient could walk on crutches, supporting himself in part on the left leg. The lumbar pain had largely disappeared.