The processes of pregnancy make a deep impression on woman’s entire nervous system, and more especially on her mental functions. This is especially noticeable in the case of primiparæ. The fact is easily understood, for a woman is filled with expectation and anxiety concerning the unknown event, the complete revolution in her organization, the powerful impressions on her physical ego, the formation of a new being within her womb. How many joyful hopes, how many distressing fears, are connected with that which is about to take place, with the act of creation within her bosom; what changeful glimpses into the future, on the one hand the gladness, on the other the terror, of motherhood; often, also, the anxious doubts as to the probable sex of the newcomer. Consider, too, the stormy sensations experienced by a woman who, unmarried, has become pregnant contrary to her desires and expectations, especially one in a poverty-stricken condition—consider the agonizing thoughts in such a case regarding the consequences of giving birth to a child. It is only to be expected that in pregnant women in general there will almost always be increased irritability of the nervous system combined with a tendency to the rapid variation of emotional states. _Neumann_ found, in almost all the pregnant women he examined in respect to the point, that there was an increase of the knee-jerks, as a manifestation of the general increase of nervous irritability. Nor does this change depend upon mental influences exclusively; there are other factors, such as the reflex processes aroused by the enlargement of the uterus, and also the changes in the composition of the blood which occur during pregnancy, and cannot fail to have an influence on the nutrition of the brain. Finally, also, the deposit of carbonate of lime on the inner surfaces of the cranial bones (the parietal and frontal bones) which occurs during pregnancy, may be regarded as having some casual connection with the changes in the nervous system; and, again many authors assume that the cerebral circulation is influenced by the formation of the placental circulation. The pathological consequences of pregnancy, as far as they affect the nervous system, take the form of neuralgia and of peripheral neuritis of various nerves, of chorea, of disturbances of the sense organs, and of actual psychoses. Peripheral neuritis in pregnant women affects chiefly the lower extremities, but has been observed in the arms also; it is characterized by muscular wasting with reaction of degeneration, by trophic disturbances, and by disorders of sensation. A cure may ensue even during the pregnancy, but in other cases the illness persists until after parturition and on into the puerperium. To the same cause _Windscheid_ assigns the paræsthesias of pregnancy, burning, prickling, and numb sensations of the finger-tips, less commonly of the toe-tips; these sensations are continuous, not paroxysmal, and cause very great suffering.