It must not be supposed that there is a sharp line of demarcation between this period and the last; nevertheless, there are certain well-marked differences, both in their general tendencies, and as regards the local varieties which are commonest in each. We shall discuss the latter point farther on. At present, it is interesting to remark on the general freedom of the busy middle period of life from first attacks of neuralgia. A person who has had neuralgia previously may, and very likely will, during this epoch, be subject to recurrence of the old affection under stress of exhaustion of any kind. But it is very rare, in my experience, for busy house-mothers or fathers of families to get first attacks of neuralgia during this period of life. It is not the way in which a still vigorous man's nervous system breaks down, if it breaks down at all. Men frequently do break down, of course, at an age when their tissues generally are sound enough, and there is no reason, except on the side of their nervous system, why they should not remain in vigorous health for years. But it is greatly more common for the nervous collapse to take the form of insanity, or hypochondriasis, or paralysis, then that of neuralgia. If a man has escaped the latter disease during the period when the growth of his tissues was active, it is not very often that he falls a victim to it till he begins, physiologically speaking, to grow old. 4. _Neuralgias of Declining Bodily Vigor._--The period here referred to is that which commences with the first indications of general physical decay, of which the earliest which we can recognize (in persons who are not cut off by special diseases) is perhaps the tendency to atheromatous change in the arteries. The first development of this change varies very considerably in date; but whenever it occurs it is a plain warning that a new set of vital conditions has arisen, and especially notable is its connection with the characters of the neuralgic affections which take their rise after its commencement. The period of declining life is pre-eminently the time for severe and intractable neuralgias. Comparatively few patients are ever permanently cured who are first attacked with neuralgia after they have entered upon what may be termed the "degenerative" period of existence. I mentioned the existence of commencing arterial degeneration as the special and most trustworthy sign of the initiation of bodily decay; but it is needless to say that this change is often not to be detected in its earliest stage. Something has been done of late years, however, to render its diagnosis more easy. Not to dwell upon the phenomenon of the arcus senilis, which though of a certain value is confessedly only very partially reliable, we may mention the sphygmographic character of the pulse as possessing a real value in deciding the physiological status of the arterial system. There is a well-known form of pulse-curve, square-headed, with marked