The nervous disturbances dependent upon the processes of the puerperium are numerous and severe. According to _Windscheid_, four types of affection of the motor nerves may arise at this period. 1. Pressure-paralysis may occur in cases of generally contracted pelvis, or even in the absence of such contraction in cases of prolonged labor, from the pressure exercised by the child’s head upon the intrapelvic nerves, and above all on the great sciatic nerve; pressure-paralysis may also result from obstetric operations, and especially from forceps delivery. The symptoms of pressure-paralysis consist chiefly of paralysis of the extensors of the feet and the toes; sensory symptoms are usually wanting. 2. Inflammatory infective paralyses, due to the extension to adjacent nerves of puerperal inflammation of the pelvic connective tissue. 3. Acute multiple neuritis, occurring either during the latter half of pregnancy or a few days after delivery, and affecting not only the nerves of the lower extremities, but those of remote regions, even the cranial nerves. 4. The rare puerperal hemiplegia due to cerebral hæmorrhage, occurring usually at the time the patient leaves her bed after delivery; puerperal hemiplegia may also arise from embolism consecutive to endocarditis, which may itself have originated before the termination of the pregnancy. Other puerperal diseases of the nervous system requiring mention are, on the one hand, tetany, occurring during lactation, and permitting of a favorable prognosis, and on the other, the infective puerperal tetanus, the prognosis of which is exceedingly unfavorable. Finally, the puerperal state has to be considered as a factor in determining the onset of psychoses. The puerperal psychoses are for the most part dependent upon the great loss of blood occurring during delivery, leading to anæmia and increased irritability of the brain, in association also with the circulatory disturbances that arise in the central nervous organs in consequence of the sudden emptying of the abdomen by the act of childbirth; but additional causes of mental disorders are to be found in the changes in the composition of the blood that occur during pregnancy, and the influence of these changes upon the nutrition of the brain. Inherited predisposition plays its usual part in these cases; and accessory factors in producing mental disturbance during the puerperal state are to be found in puerperal infection, eclampsia, osteomalacia, and emotional shock.