The importance of the genital organs is shown by the vast nerve-supply sent to them. When this great nerve-tract becomes atrophic, so that it can no longer transmit the higher physiologic orders, all parts of the sympathetic system must be unbalanced, until a new line, the next line of least resistance is established. And Robinson believes that this is the explanation of the many pathologic manifestations of every viscus at the menopause; that is, "the irritation which arises by trying to pass more nervous impulses over plexuses than normal gives origin to what is unfortunately known as functional disease. It is just as organic as any disease, only we are unable to detect it." Chemical changes in the blood and tissues are constant vital phenomena; increased oxidation causes increased activity of the circulation, increase of temperature, increase of urea and carbonic acid in the economy from retrograde changes, and, finally, during menstrual life the flow of blood from the uterus carried off the effete materials from the highly charged system. The elimination of albuminoids, as shown by the altered condition of the blood after menstruation, is greater than can be accounted for by the blood discharged. When the menopause is attained suddenly, the retention of such albuminoid substances must act toxically. Hence the resulting clinical fact that sudden cessation of the menses is, in the majority of cases, attended with pronounced symptoms of discomfort, and it is in these cases that untoward results are most likely. James Oliver believes that the catamenial flow eliminates from the body substances whose presence in the blood would exert a deleterious influence on the animal economy. The Prominent Symptoms of the Menopause.-- Christopher Martin holds that the symptoms of the change of life are produced largely by a condition of instability and increased excitability of certain other cerebrospinal centers directly brought about by failure of the menstrual center, and adds: "It is probable that the ovaries, like the liver and thyroid gland, modify the blood circulating through them, and add to the blood some peculiar product of their metabolism. It may be that some of the climacteric symptoms are due to the loss of this substance from the system." Arthur Johnstone's theory of the symptoms of the menopause is that the lining membrane of the uterus atrophies and becomes old cicatricial tissue, and sinks into quiet decay. The nervous system begins to readjust itself; but no longer having free outlet through the soft, lymphoid tissues of the uterus, the wave pressure meets with resistance and a choppy sea results. Vertigos, bilious attacks, and so forth are nothing more than reflex waves. The weakest organ of the individual is the one that generally suffers. And that the kidneys, which all along have borne the brunt of life, should now show positive signs of disease is natural.