Concerning the health of the German girls, as compared with American girls, the German physicians have not sufficient information to warrant any statement. But the health of the German girls is commonly good except in the higher classes in the great capitals, where the same obnoxious agencies are to be found in Germany as in the whole world. But here also there is a very strong exception, or, better, a difference between America and Germany, as German girls are never accustomed to the free manners and modes of life of American girls. As a rule, in Germany, the mother directs the manner of living of the daughter entirely. I shall have more and better information some time later. Yours, H. HAGEN. A German lady, who was educated in the schools of Dantzic, Prussia, afforded information, which, as far as it went, confirmed the above. Three customs, or habits, which exert a great influence upon the health and development of girls, appear from Dr. Hagen's letter to make a part of the German female educational regimen. The first is, that girls leave school at about the age of fifteen or sixteen, that is, as soon as the epoch of rapid sexual development arrives. It appears, moreover, that during this epoch, or the greater part of it, a German girl's education is carried on at home, by means of lectures or private arrangements. These, of course, are not as inflexible as the rigid rules of a technical school, and admit of easy adjustment to the periodical demands of the female constitution. The second is the traditional motherly supervision and careful regimen of the catamenial week. Evidently the notion that a boy's education and a girl's education should be the same, and that the same means the boy's, has not yet penetrated the German mind. This has not yet evolved the idea of the identical education of the sexes. It appears that in Germany, schools, studies, parties, walks, rides, dances, and the like, are not allowed to displace or derange the demands of Nature. The female organization is respected. The third custom is, that German school-girls are not invited to parties at all. "All this comes after the school," says Dr. Hagen. The brain is not worked by day in the labor of study, and tried by night with the excitement of the ball. Pleasant recreation for children of both sexes, and abundance of it, is provided for them, all over Germany,--is regarded as necessity for them,--is made a part of their daily life; but then it is open-air, oxygen-surrounding, blood-making, health-giving, innocent recreation; not gas, furnaces, low necks, spinal trails, the civilized representatives of caudal appendages, and late hours.