In 1906 Alzheimer reported the case of a woman, æt. 51, who, in addition to the expression of ideas of suspicion and jealousy, failed mentally to such an extent that she was unable to find her way about her own home. During her hospital residence she was perplexed, disoriented for time and place, and had difficulty in understanding and in expressing her thoughts. There were delirious phases, during which she was hallucinated. Her power of retention was greatly impaired. She showed paraphasia and perseveration. The illness persisted for a period of four and a half years, and at the time of her death she suffered from contractures. The post-mortem examination showed a striking alteration of the neurofibrils: “In an otherwise normal cell there appear at first one or more fibrils, which on account of increased thickness and increased stainability stand out prominently. In the further course of the alteration many neighbouring fibrils are similarly affected. These then form thick bundles, which gradually come to the surface of the cell. Finally the nucleus and cell disintegrate, and only a tangled bundle of fibrils remains to indicate the site of a former ganglion cell.” In addition, throughout the entire cortex, especially in the outer layers, there were many miliary foci or plaques.