MENSTRUATION. 301 



necessary to quote. The occurrence of pregnancy after the 

 age of fifty or fifty-five is certainly doubtful. 



Menstruation. 



It is unnecessary to discuss farther the correspondence 

 between menstruation in the human female and the condi- 

 tion of heat in the lower animals, as we have already seen, 

 under the head of ovulation, that these two conditions are 

 essentially identical. In the lower animals, the female will 

 admit the male only at the period of heat ; and in some ani- 

 mals in the savage state, it is only at this time that the male 

 is capable of copulation. The variations in sexual tempera- 

 ment in the human female are so considerable, and the senti- 

 ments toward the opposite sex are so subordinate to artificial 

 conditions of society and civilization, that it is difficult to es- 

 tablish a parallel, in this regard, between her and the lower 

 animals. Some females rarely or never experience sexual 

 excitement and have no orgasm during intercourse; while 

 others are capable of sexual ardor at any time. Women who 

 are in the habit of promiscuous relations with the other sex 

 frequently lose the sexual feeling and simulate excitement 

 during coitus. It is very difficult, indeed, to say positively 

 how far the facts observed in the lower animals are appli- 

 cable to the human subject, as we must depend largely upon 

 statements which, of themselves, are entitled to but little con- 

 sideration. It is nevertheless true that, in some women, sex- 

 ual desire is decidedly marked just after the cessation of the 

 menses, and in many, it really exists at no other time. Still, 

 mercenary or other considerations may induce women to ad- 

 mit intercourse at any time, and the sexual orgasm, and even 

 fecundation, may at any time occur. As a rule, the female 

 yields to advances made by the male, and is reputed to expe- 

 rience a less degree of sexual desire and ardor, though this has 

 marked exceptions. It is probably true that, eliminating, as 



Obstetrics, New York, 1874, vol. vi., p. 571, et seq. ; and, Transactions of the 

 Philadelphia Obstetrical Society. Ibid., p. 637, et seq.) 



