_Senile Dementia._--Textbooks and articles on old age generally state that the changes in psychic personality that occur are identical with normal ones, only in intensified degree. The traits most commonly specified are: limitation of the circle of ideas, qualitative and quantitative loss of elasticity, pauperization of interests, dwelling on _gemütlicher_ activity, lapses in attention, Ziehen’s “egocentric narrowing of the life of feeling,” perhaps hypochondriacal symptoms, mistrust, inflexibility, lowered power of activity, and resistance against everything that is new. Works in general pathology, like Hübner, Ranschenburg, Balint, and Lieske deal with these in more detail. In general, there is a sinking of psychic activity and change of character which suggest physiological involution, and these occur--in some, earlier, and in some later. If we compare these psychic traits it would seem that there is only a quantitative difference between normal old age and senile dementia, the latter having only gone farther or faster. The decision of this question is for pathological anatomy and here Spielmeyer’s studies coincide with those of Simchowicz. The older an individual is, the less sharply either clinically or anatomically can it be decided whether it is normal or senile dementia. There are the same changes in the nerve cells, neuroglia, the myelin sheaths, and the mesoderm tissues; also in the blood vessels the changes are identical, the difference being only in degree. Fatty degenerations of the ganglion cells also occur in both. Sclerotic changes of elements are general. The neuroglia cells with normal seniles have lipoidal material in abundance, and the gliafibers, especially in their upper surfaces in the cortex, are increased. The walls of the blood vessels have undergone the same regressive changes and acquired the same fatty material by infiltration, and even the so-called senile plaques are found. Thus in general there is the same using up of the central organs. We are, thus, not yet in a position to determine from the brain alone, if we know nothing of the individual, whether he was a senile dement or a very old man. The older a man is, the more we find the Redlich-Fischer plaques. Thus the senile dement shows neither anatomically nor clinically any essential differences from those found in the normal senium.