Senescence, the Last Half of Life

by G. Stanley Hall

As to mental manifestations, this author says they are extremely variable, insidious, and have a very wide latitude. The vitality of the mind should be far greater than that of the body. Old age dulls conscience, may bring vanity and new ambitions, petulance, irritability, misanthropy, and slows down activity. But the best average barometer of mental failure is memory, the loss of which comes as an advance guard of many symptoms. The old have no faith in the young, for example, Virchow and Agassiz would not accept evolution. There is a universal tendency to overeat, although we should “descend out of life as we ascended into it, even as to the child’s diet.” The first sign that food must be reduced is increased blood pressure. If only lower ideals were exercised in early life, the reversion is ominous. Age is never chronological except in the legal sense. It is often called a vascular problem. The old have immunity from certain diseases such as eruptive fevers, typhoid, phthisis, and old tissues do not seem to be good media for these disease agencies, but age is very prone to pneumonic infections and erysipelas.

As to premature senility, in general its symptoms are identical with those of mature senility. The old are particularly prone to flush under very slight emotional strain and cannot throw off care or control patience. As to the causes of premature senility, abuse rather than use is the key. There is an unhealthy tendency to force decline by overtaxing the body and the nerves. It is those who do this who take the pace that kills, taxing themselves beyond their capacities. Alcohol and syphilis are specific forerunners of arteriosclerosis but overeating is worse than alcohol, especially of meat. “Most people eat about twice as much as they need, and the high cost of living is the high cost of overeating.” The dietitian’s table of food values should always be consulted but there has to be wide latitude for individual adjustments. Modern efficiency ideals bring high pressure. Change is the greatest regulator. We now relegate older men to innocuous desuetude to give the younger a chance to forge ahead.

As to the proper sphere of the aged, there have been opposite views. Perhaps there are no more than five hundred really great men in history who were clearly above mediocrity. Galton thinks 70 per cent of their work was completed before 45, and 80 per cent before 50. Dorland analyzed four hundred celebrities and concluded the average age of the commencement of their activities was 24 years—in musicians perhaps as early as 17 and scientists at 32. Science is hard and requires a large fund of experience and knowledge. The greatest average for activity in all endeavors together is about 40. To enjoy life after 40 one must have attained some degree of success, for the saddest thing is to reflect on many years of effort and no accomplishment.

As to medico-legal aspects, eccentricities may prevent the aged testator from being allowed the right of testament, but in general the mental symptoms of advanced senility differ from senile dementia only in degree.

As to the future of old age, those who are not senile have a distinct place as counsellors. They should excel in strength of reason, cool judgment, and breadth of view. One may be past the age of discretion before one is old in years. The conservative tendencies of this period are valuable as checks to the exuberant impulses of youth. The dependent aged are a burden and their support is often a handicap. With modern progress the number who fail to keep pace increases with the speed of advance and this has to be complemented by the fact that the old are increasing in numbers. With few exceptions man lives longest of any animal. Everything does grow old except vanity and the more perfect the organization the earlier the aging and the sooner the end, for it is the perfect more surely than the good that die young. Every stage of life is marked by a limit, but this limit varies greatly. “Every man past forty is a fool, physician, or a divine, and most people practically throw away their lives.” The lower the scale of education, the greater the hazard of life. Longevity among pure muscle workers is rare. We know little of the influence of race, but we know that women, lean people, the married, the religious, on the whole, live longest. Haeckel believed in “medical selection” and pointed to the fact that some have greater power to resist disease. Is this desirable for the integrity of the race? “Death is a process, not an event.” Man does begin to die early in life. The bicycle rider has to keep going to keep erect, and so the old must keep working. The first vacation is often fatal.

Hastings Gilford[147] regards the development of the human body as a whole, or of any portion of the body, as describing a curve that ascends from the time of the union of the two genetic elements to a maximum at which there is the greatest development of specialization in function and the least in the general characters, such as those of multiplication. The curve then begins to descend, with a gradual and progressive loss of differentiation in form and function and an increasing tendency of certain cells to multiply. Decay of certain cells during advancing age leads to their becoming bodies foreign to their host, and this, in turn, calls forth the phagocytes which, walling off the foreign body, become themselves transformed into fibrotic tissue. The three characters of old age are decay, fibrosis, and proliferation of non-specialized cells. As the more specialized cells retrogress, with the loss of specialization they take on an increased tendency to multiplication. “Reversion ... is the keynote of the proliferation in old age wherever it occurs.”

Granting the foregoing statements regarding the anatomy and biology of old age to be true, Gilford even believes that we can explain cancer in terms of senility. He says: “Thus the typical cancer is made up of a collection of cells native to the part, but of more embryonic type, and these cells are surrounded by collections of round indifferent cells derived from fibrous tissue and from other low class structures, such as endothelium and leucocytes.” The fibrous tissue, moreover, is often increased, as it is in the senile organ. These changes may be interpreted as follows. Certain somatic cells become aged while the tissues around them are still in a state of comparative youth. They express their senility by returning to a more embryonic form, and as they do so they increase in number, the faculty of multiplication being one of the manifestations of regression. But as this qualitative change takes place they become alien to their surroundings and, as foreigners or rebels, stimulate into action the mechanism of phagocytosis. Not only is there an incursion of lymphocytes into the parts but the connective tissue and endothelial cells in their vicinity revert to their embryonic state and begin the work of phagocytosis. But as a fact they have to deal with neither the effete products of molecular degeneration nor with an inert foreign body, for though virtually strangers cancer cells are by no means inactive. Hence the attack is abortive, except in so far as the phagocytes, by forming new fibrous tissue, tend mechanically to limit the proliferation of the cancer cells. For in the meantime the fixed connective tissue cells are themselves rapidly proliferating, with the result that when they cease their activity and return to their resting stage, groups of cancer cells are cut off by intersecting bundles of fibrous tissue, while the whole mass is surrounded by an incomplete capsule of the same structure. This tends to limit the encroachment of the growing cancer, and were it not for the lymph spaces or capillaries, which are the gaps through which the growing cells escape, no doubt the limitation and strangulation of cancers would occur far more often than they do.

It will be noticed that the more nearly the cells of a cancer approach the embryonic state the more rapid will be the growth, and the less opportunity for fibrosis the more malignant the cancer. Gilford maintains for this unique theory that it is satisfactory, based as it is, upon facts reasonably interpreted, and that it covers all of the ground.

Horst Oertel[148] holds that the origin of cancer in the liver is a transformation of multiple groups of its cells and that there was a direct change of atrophic, degenerative, existing liver cells into cancer cells while they were still in perfect continuity with each other. In this degeneration of normal to cancer cells the former lose their typical protoplasm, the nucleus grows small and its chromatin structure faint, till little of it remains, with only a faint rim of surrounding protoplasm. At this point some of these cells show a very striking change in rapid, irregular production of rich chromatin arranged in a less structural definition and leading to marked enlargement of them. There is a first destructive stage with extensive loss and granular degeneration of protoplasm. In the second, incipient regeneration shows and the nucleus is markedly enlarged, with irregular production of small chromatin granules; while in the third stage, the carcinomatous, we have a new type of cell following new laws and breaking with the former physiological arrangement and structure. The new functional type involves rapid independent growth with a distinct disregard of original source and surroundings and with progressive loss of continuity and power to secrete bile.

Thus he, too, holds that cancer seems an embryonic reversal and involves no specific changes but is a phenomenon of senescence, a degeneration of cells with an unequal decline in cell functions. Thus races of cells develop that lack the differentiation of undegenerated cells but are still endowed with vegetative and reproductive properties. His idea that the degeneration and injury to cells could be responsible for growth, was severely criticised. It was said that any change that meant injury could never be progressive but would lead to diminution of functions. But the author still holds that injury may produce growth of all kinds of tumors, for example, in the pancreas, growth and cell division is dependent upon the release of certain inhibitory influences that exist in the normal well-balanced cells. This upset may be caused by certain liquid solvents but the idea of formative stimuli on the whole seems to hold; namely, cancer cells arise out of degenerative and atrophic changes, so that injury, degeneration, and growth do not exclude each other but stand in genetic relation.