I. L. Nascher[151] thinks that too little study has been given to the physical changes in involution and still less to the mental. Occasionally the approach of senile dementia gives rise to forensic questions. There is a general neglect of the subject of geriatrics. This author thinks the brain reaches its limit of physical development at about 30, but Bunsen and Mommsen both did much of their best work after their brain had grown quite atrophied, so that quality comes in. The integrity of these cells depends upon nutrition. We have few blood examinations of the aged and these do not show any marked clinical or microscopic differences between maturity and senility, while the process of senile involution rests apparently on defective nutrition of cell tissues. Those who do good work in age generally focus into one channel and their degeneration is shown in other fields. We usually do not think of our somatic state until some discomfort compels us to do so. One may have lessened interest in former hobbies or events of the day; but if impairment of reason keeps pace with that of memory, he will not know that his powers are failing. He then begins to think of his body and its preservation as more important than wealth or fame, wants to live, and gives more attention to prolonging life. There is often a change of temperament into egoism, perverseness, peevishness, loss of ambition, religiosity, inability to bear slight discomforts and depression. The child thinks little of the future, while in maturity hope tends to paint a future haloed by happiness and in senility the future is death, notwithstanding what all philosophers, poets, and preachers say. Our mental attitude is simply a resignation to the inevitable. One patient had a daughter devoted to him whose absence for a moment he could not bear, and once this so angered him that his total attitude toward her changed to one of dislike and suspicion. In another case a woman of seventy-six underwent a complete change of character. Arrogance gave way to humility; in contrast to her former independence, she now craved sympathy. Then later she changed again and made extraordinary demands upon her children, wanted the latest styles in everything, etc. In another case memory, reason, and will grew weak in an old manufacturer. He lost his way on the street, a child could divert him from his purpose, and he clung to a notebook by day and night till complete dementia came. Another man who was noted for carrying through everything he planned, even breaking up partnerships, when old became not only susceptible to advice but could be easily turned from his purpose.