In America various investigations have been carried out, showing the prevalence of disturbance in the sexual health of school girls and young women. Thus Dr. Helen P. Kennedy obtained elaborate data concerning the menstrual life of one hundred and twenty-five high school girls of the average age of eighteen ("Effect of High School Work upon Girls During Adolescence," _Pedagogical Seminary_, June, 1896). Only twenty-eight felt no pain during the period; half the total number experienced disagreeable symptoms before the period (such as headache, malaise, irritability of temper), while forty-four complained of other symptoms besides pain during the period (especially headache and great weakness). Jane Kelley Sabine (quoted in _Boston Medical and Surgical Journal_, Sept. 15, 1904) found in New England schools among two thousand girls that 75 per cent. had menstrual troubles, 90 per cent. had leucorrhoea and ovarian neuralgia, and 60 per cent. had to give up work for two days during each month. These results seem more than usually unfavorable, but are significant, as they cover a large number of cases. The conditions in the Pacific States are not much better. Dr. Mary Ritter (in a paper read before the California State Medical Society in 1903) stated that of 660 Freshmen girls at the University of California, 67 per cent. were subject to menstrual disorders, 27 per cent. to headaches, 30 per cent. to backaches, 29 per cent. were habitually constipated, 16 per cent. had abnormal heart sounds; only 23 per cent. were free from functional disturbances. Dr. Helen MacMurchey, in an interesting paper on "Physiological Phenomena Preceding or Accompanying Menstruation" (_Lancet_, Oct. 5, 1901), by inquiries among one hundred medical women, nurses, and women teachers in Toronto concerning the presence or absence of twenty-one different abnormal menstrual phenomena, found that between 50 and 60 per cent. admitted that they were liable at this time to disturbed sleep, to headache, to mental depression, to digestive disturbance, or to disturbance of the special senses, while about 25 to 50 per cent. were liable to neuralgia, to vertigo, to excessive nervous energy, to defective nervous and muscular power, to cutaneous hyperæsthesia, to vasomotor disturbances, to constipation, to diarrhoea, to increased urination, to cutaneous eruption, to increased liability to take cold, or to irritating watery discharges before or after the menstrual discharge. This inquiry is of much interest, because it clearly brings out the marked prevalence at menstruation of conditions which, though not necessarily of any gravity, yet definitely indicate decreased power of resistance to morbid influences and diminished efficiency for work.