Edgar says that “there is no doubt that the presence of puerperal sepsis in many of the cases is something more than a coincidence.” Alienists assure us that since the introduction of antisepsis into midwifery the frequency of puerperal insanity has been marvelously diminished. Many cases of this type of psychoses are said to exhibit more the nature of delirium—such as is seen, for instance, in typhoid fever—than of actual insanity. Again, the coincidence of severe local infection has often been remarked, and gives color to the toxic theory; while a further coincidence of insanity of the puerperium with puerperal mastitis, phlebitis, and other inflammations remote from the genitals helps the assumption of this point of view. Of other special contributory factors may be mentioned the exhaustion which follows delivery, extreme prostration being a well known cause of certain psychoses or of low delirium. In this connection should be mentioned the influence of post-partum hemorrhage. In women already disposed to insanity the physiological adjustment which follows childbirth is doubtless sufficient to set up mental disorder. Other conditions which excite puerperal psychoses are the painful emotions. Lewis, of Chicago, who, we must remember, does not call this a medical entity, says: “The inciting factor of insanity arising during the puerperal period are due, in from 70–80 per cent of the cases to either toxemia or infection. In the remainder no exciting cause beyond the general disturbance due to the bodily state can be assigned, * * *. The insanity arising in the lactation period is essentially due to exhaustion and inanition,” occurring in women of the poorer, harder working, more improperly fed classes. “General weakness from other causes, such as may follow severe post-partum hemorrhage or recovery from septic infection, may be the exciting element.” Before we close the subject of its occurrence and cause, let us consider the illegitimacy and the number of the pregnancy, etc. Of 203 strictly puerperal cases collected by Jones, of London, about 10 per cent were single and 33 per cent were primiparal. One patient had an attack of insanity after each of her twelve children and another with each of nine, both becoming subject to chronic incurable insanity at the climateric. In lactation cases the insanity did not commonly follow a first confinement, but appeared to be due to the strain of frequent pregnancies and the exhaustion of long continued nursing. Puerperal insanity is most common between twenty-five and twenty-eight; lactational between thirty and thirty-four.