[Illustration: FIG. 2.--Section of medulla oblongata from case of gas poisoning, stained by Nissl method, showing the swollen cells of the nucleus ambiguus. Observe the enlarged, clear, eccentric nucleus; the surrounding cytoplasm shows an absence of Nissl granules. In not a single cell is the nucleus seen in the centre as it should be. (Magnification 450.)] [Illustration: FIG. 3.--Section of medulla oblongata from case of shell-shock with burial, stained by Nissl method, showing the swollen cells of the nucleus ambiguus. Observe the enlarged, clear, eccentric nucleus; the surrounding cytoplasm shows an absence of Nissl granules. In not a single cell is the nucleus seen in the centre as it should be. (Magnification 450.)] [Illustration: FIG. 4.--Section of third cervical segment of spinal cord from case of concussion, stained by Nissl method, showing the medium group of anterior horn cells corresponding to the nucleus diaphragmaticus. They show certain amount of perinuclear chromatolysis. But all the cells exhibit the Nissl granules. Even at the seat of concussion, the fourth segment, an external group of cells remains showing Nissl granules. Concussion therefore does not destroy the Nissl granules. Probably the cells of the nucleus diaphragmaticus show a certain amount of chromatolysis because they were continually discharging impulses along the phrenic nerves, and the few cells that were left of the nucleus had therefore much more work to do. (Magnification 300.)] Mott suggests that the sudden death of the case may be due to a hemorrhage into a sheath of a fair-sized vessel in the median raphe of the bulb; the general venous congestion; and the almost complete chromatolysis of the vago-accessorius nucleus (adjacent hypoglossal nucleus normal). According to Mott, also, many Shell-shock symptoms, _e.g._, headache, giddiness, amnesia (anterograde and retrograde), dizzy feelings, lack of power of attention, and fatigue, stupor, inertia, mental confusion, terrifying dreams, are to be explained on the basis of capillary anemia and chromatolytic changes. Mine explosion. Ecchymoses; no bone or visceral consequences seen at AUTOPSY (third day after explosion) except SUBDURAL HEMORRHAGE and PUNCTATE HEMORRHAGES OF BRAIN. =Case 198.= (CHAVIGNY, January, 1916.)