that it is due, as I have suggested, to natural selection.] Sometimes a finger in the vagina could not be felt at all.  One woman, when a catheter was introduced into the anus, said it might be the vagina or urethra, but was certainly not the anus. (Calmann remarks that he was careful to put his questions in an intelligible form.) The women were only conscious of the urine being drawn off when they heard the familiar sound of the stream or when the bladder was very full; if the sound of the stream was deadened by a towel they were quite unconscious that the bladder had been emptied. [In confirmation of this statement I have noticed that in a lady whose distended bladder it was necessary to empty by the catheter shortly before the birth of her first child—­but who had, indeed, been partly under the influence of chloroform—­there was no consciousness of the artificial relief; she merely remarked that she thought she could now relieve herself.] There was some sense of temperature, but sense of locality, tactile sense, and judgment of size were often widely erroneous.  It is significant that virgins were just as insensitive as married women or those who had had children.  Calmann’s experiments appear to be confirmed by the experiments of Marco Treves, of Turin, on the thermoesthesiometry of mucous membranes, as reported to the Turin International Congress of Physiology (and briefly noted in Nature, November 21, 1901).  Treves found that the sensitivity of mucous membranes is always less than that of the skin.  The mucosa of the urethra and of the cervix uteri was quite incapable of heat and cold sensations, and even the cautery excited only slight, and that painful, sensation.

In further illustration of this point reference may be made to the not infrequent cases in which the whole process of parturition and the enormous distention of tissues which it involves proceed throughout in an almost or quite painless manner.  It is sufficient to refer to two cases reported in Paris by Mace and briefly summarized in the British Medical Journal, May 25, 1901.  In the first the patient was a primipara 20 years of age, and, until the dilatation of the cervix was complete and efforts at expulsion had commenced, the uterine contractions were quite painless.  In the second case, the mother, aged 25, a tripara, had previously had very rapid labors; she awoke in the middle of the night without pains, but during micturition the fetal head appeared at the vulva, and was soon born.

Further illustration may be found in those cases in which severe inflammatory processes may take place in the genital canal without being noticed.  Thus, Maxwell reports the case of a young Chinese woman, certainly quite normal, in whom after the birth of her first child the vagina became almost obliterated, yet beyond slight occasional pain she noticed nothing wrong until the husband found that penetration was impossible (British Medical