110 first menstruat. at 11 years 144 „ 12 „ 256 „ 13 „ 860 „ 14 „ 366 „ 15 „ 284 „ 16 „ 144 „ 18 „ 72 „ 19 „ 40 „ 20 „ ———— 1776 total. At what age the remaining five first menstruated, the table does not show. On the whole, its results may be regarded as very similar to those of Mr. Robertson’s table, before given. Dr. Guy, of London, gives a table of the ages at which menstruation commenced of 5,062 cases, 2,905 being of England, 1,825 of France, 332 of Germany; the total numbers being as follow: 1 first menstruat. at 5 years 1 „ 7 „ 2 „ 8 „ 15 „ 9 „ 48 „ 10 „ 263 „ 11 „ 368 „ 12 „ 554 „ 13 „ 839 „ 14 „ 926 „ 15 „ 751 „ 16 „ 574 „ 17 „ 379 „ 18 „ 173 „ 19 „ 111 „ 20 „ 29 „ 21 „ 14 „ 22 „ 10 „ 23 „ 4 „ 24 „ There is one topic connected with this subject which I cannot here enlarge upon, but which I will simply refer to by quoting the remarks of a certain author who has given much attention to the subject. Dr. Ray, author of a work on the “Medical Jurisprudence of Insanity,” observes, “that the evolution of the sexual functions is very often attended by more or less constitutional disturbance, especially in the female sex, is now a well-established physiological truth. The shock seems to be felt chiefly by the nervous system, which experiences almost every form of irritation, varying in severity from the slightest hysteric symptoms to tetanus, St. Vitus’ dance, and epilepsy.” “And when we bear in mind, also, that general mania is sometimes produced by this great physiological change,” continues this author, “it cannot be deemed an extraordinary fact that partial mania, that partial acts, inciting to acts of incendiarism or murder, should be one of its effects.” LETTER III. OF MENSTRUATION.