There would be no way of controlling or of preventing abortion in the event of the implantation of a second fetus in a uterus already occupied by one in a process of development, even if the condition were known to exist. The case herewith reported is of great interest, nevertheless, as demonstrating that abortion or miscarriage may be produced by superfetation. It might even be a frequent, though often overlooked, cause.
Mrs. M. G., aged 22, of previous healthy condition, menstruated regularly and normally prior to marriage. The first child, born May 7, 1916, and the second child, born April 10, 1917, were delivered normally. Following the birth of the second child, menstruation began during the latter part of May, continued for fifteen days, and was irregular in quantity. During the latter part of July the patient began to menstruate again, and complained of a severe pain over and on