_Wounds of the Brain._—Laceration of this organ to a slight extent, with more or less extravasation of blood, often takes place, without external wound, and when the patient has symptoms of concussion only. In such cases, the blood may be absorbed, and the læsion repaired, without permanent impairment of the sensorial functions. Wounds of it, along with fracture of the skull, are often very extensive; and portions of its substance may be either severely injured, or entirely separated. Loss of substance, even to a considerable extent, in the upper part of the hemispheres, may occur, without bad symptoms or consequences ensuing. The exposed surface of the brain granulates, and is healed as other parts of soft structure. Generally, however, untoward symptoms result sooner or later in such cases. Hemorrhage occurs from the injured part, and a clot protrudes from the external wound. Or the cerebral substance in the neighbourhood of the wound softens, and becomes converted into a semifluid mass, often mixed with pus; and a fungous growth, connected with the disorganised matter, gradually protrudes through the aperture in the cranium, and is repressed with difficulty. If removed by knife or ligature, it is rapidly reproduced. Pressure is the only means left by which to attempt its retardation; and this, too, is generally ineffectual; for if not very moderate, the effects of compression extend from the fungus to the whole of the brain, and an impairment of the sensorial functions in a greater or less degree necessarily results. The formation of such a growth is generally attended with shivering, sickness, and fever, by a weak, rapid, and irregular pulse; the strength declines, convulsions and delirium supervene, and coma terminates the symptoms.[26]