out and is well understood. Again this warrants the expectation that, with more extended and penetrating investigations in a field of research which is really just at its beginning, we shall understand the physics and chemistry of prolongation of life of cells and tissues in a great many cases where now we know nothing about it. One further point and we shall have done with this phase of our discussion. The experimental culture of cells and tissues in vitro has now covered practically all the essential tissue elements of the metazoan body, even including the most highly differentiated of those tissues. Nerve cells, muscle cells, heart muscle cells, spleen cells, connective tissue cells, epithelial cells from various locations in the body, kidney cells, and others have all been successfully cultivated in vitro. We may fairly say, I believe, that the potential immortality of all the essential cellular elements of the body either has been fully demonstrated, or else has been carried far enough to make the probability very great that properly conducted experiments would demonstrate the continuance of the life of these cells in culture to any definite extent. It is not to be expected, of course, that such tissues as hair, or nails, would be capable of independent life, but these are essentially unimportant tissues in the animal economy as compared with those of the heart, the nervous system, the kidneys, etc. What I am leading to is the broad generalization, perhaps not completely demonstrated yet, but having regard to Leo Loeb's work, so near it as to make little risk inhere in predicting the final outcome, that all the essential tissues of the metazoan body are potentially immortal. The reason that they are not actually immortal, and that multicellular animals do not live forever, is that in the differentiation and specialization of function of cells and tissues in the body as a whole, any individual part does not find the conditions necessary for its continued existence. In the body any part is dependent for the necessities of its existence, as for example nutritive material, upon other parts, or put in another way, upon the organization of the body as a whole. It is the differentiation and specialization of function of the mutually dependent aggregate of cells and tissues which constitutes the metazoan body which brings about death, and not any inherent or inevitable mortal process in the indidividual cells themselves. 3. SENESCENCE A careful and unprejudiced examination will suffice to convince anyone of open mind, I think, that much of the literature on senescence is really of no fundamental importance, because it has unwittingly reversed the true sequential order of the causal nexus. If cells of nearly every sort are capable, under appropriate conditions of living indefinitely in undiminished vigor, and cytological normality, there is little ground for postulating that the observed senescent changes in these cells while in the body, such as those described by Minot and others, are expressive of specific and inherent mortal processes going on in the cells, or that these cellular processes are the cause of senescence, as Minot has concluded. It would rather appear that these visible cytological changes are expressive of effects not causes, and that they are the effects of the organization of the body as a whole as a system of mutually dependent parts, and not of specific, inherent and inevitable cellular processes. Cells in culture in vitro, as we have seen, do not grow old. We see none of the characteristic senescent changes in them. From these facts it is a logically cogent induction to infer that when cells show the characteristic senescent changes, which were discussed in the preceding paper, it is because they are reflecting in their morphology and physiology a consequence of their mutually dependent association in the body as a whole, and not any necessary progressive process inherent in themselves. In other words we may justifiably, in the light of our present knowledge as I believe, regard senescence as an attribute of the multicellular body as a whole, consequent upon its scheme of morphologic and dynamic organization. This attribute is reflected morphologically in the component cells. But it does not originate in the cells, nor does it ever occur in the cells when they are removed from the mutually dependent relationship of the organized body as a whole. In short senescence is not a primary attribute of the physiolog ical economy of cells as such. If this conception of the phenomenon of senescence is correct in its main features, as I believe it is, it shows the essential futility of attempting to investigate its causes by purely cytological methods. On the other hand, by clearing away the unessential elements, it indicates where research into the problem of causation of senescence may be profitable. . MOTION PICTURES AND CRIME By Dr. A. T. POFFENBERGER COLUMBIA UNIVERSITY, NEW YORK CITY NE of the surprising things about the wave of crime which is reported to be raging throughout the country is the large number of very young persons found implicated in crimes of all sorts. Much attention has recently been given to the matter in newspaper articles and editorials, and blame is placed rather frequently upon the motion picture. Various sorts of censorship have been proposed, most of them drastic in form. The following article taken from a recent issue of the New York Times will serve as an illustration: Motion pictures portraying criminals at work have been barred inChief of Police announced today that three weeks ago he had given orders to movie censors not to issue permits for any screen drama that showed a crime committed, even though the end of the picture might show the criminal in a prison cell. "It will make no difference whether the criminal shown is a hero or a villain," said the chief. "Even the showing of a policeman disguised as a burglar is taboo." The order became public when three youthful robbers, who were sentenced to the State Reformatory, said their crimes had been inspired by a "crook" moving picture. Prohibitions and censorships of any sort are distasteful to the American people, except in cases where the general welfare can be proved to be at stake. Therefore an inquiry into the accusations that have been made against the motion picture seems justified at this time. when attention is being centered upon the means of crime prevention. The question is a psychological one, and concerns the effects of motion picture experience upon the mind of the young person. The average adult can not interpret the reactions of a child in terms of his own reactions, because there are fundamental differences between the two. A knowledge of child psychology is needed to understand what the motion picture means to the child. As an agent of publicity, with its immense daily audience of young people, it has great possibilities for creating and developing in them a spirit of true Americanism, a respect for law and social order which are recognized as essentials for a democracy. Rightly used, the motion picture is indeed one of the most powerful educational forces of the twentieth century. Its possible influence in the Americanization of our foreign population, through a medium which shall be intelligible to all, regardless of race, is scarcely yet realized. But wrongly used and not carefully guarded, it might easily become a training school for anti-Americanism, immorality and disregard for law-a condition in which each individual is a law unto himself. We have therefore, in a sense, to meet an emergency, to begin in time to make of this truly public school the kind of educational force that it should be-to prevent rather than to prohibit. In a consideration of the young, we must not fail to include that great class of unfortunates designated as the mentally deficient. They are individuals, who, though physically and chronologically adults, are still children mentally. The problem of the mentally retarded individual is essentially the same as that of the normal person of younger years. The moron, the highest type of the feeble-minded, usually defined as an individual whose mental development has ceased at about the age of eleven years, has most of the mental traits of the child of eleven years. He has, however, the physical strength, instincts and desires of the adult. The moron is seldom confined in an institution, because his defects are not considered by family and friends as great enough for that. As a result, this type of individual is at large, and must be protected from evil suggestions and from too complex an environment. Such persons, when the higher forms of control which they lack are supplied by guardians or are made unnecessary by simplified living conditions, may well become useful and self-supporting members of society. Without this control, they constitute a real danger, since their physical age, which may be from fifteen years up, places them in a position to act upon evil suggestions more readily than the child. What, then, are the mental characteristics of these two groups, children and mentally deficient adults, which mark them off from normal adults? One respect in which they differ from the adult is in suggestibility; another is the lack of ability to foresee and to weigh the consequences for self and others of different kinds of behavior; another is the lack of capacity and willingness to exercise self-restraint; and still another is an imagination less controlled and checked by reference to the realities. All these traits taken together make the child and the mentally deficient person especially susceptible to evil influences. That is why one expects the majority of certain kinds of crimes to be committed by persons of retarded mental development. And recent statistical studies of the relation between crime and mental defect confirm the expectation. One needs only to recall the epidemics of suicide and murder by such means as cyanide of potasium, chloride of mercury, carbolic acid and the like; to notice the likenesses in the technique of burglars at different periods of time; to note the cases of false testimony in court and false confessions of crime to realize the great suggestibility of such persons and their lack of foresight. Unlike the VOL. XII-22 normal adult, they are unable to resist the suggestions of advertisements, posters, newspapers and magazines, and of their associates. Naturally, these traits may be played upon either for good or evil. One who knows the mechanism of suggestion would expect the prevalence of crime, especially when it is advertised by these agencies of publicity, to breed more crime. Motion pictures, containing scenes vividly portraying defiance of law and crimes of all degrees, may by an ending which shows the criminal brought to justice and the victory of the right, carry a moral to the intelligent adult; but that which impresses the mind of the mentally young and colors their imagination is the excitement and bravado accompanying the criminal act, while the moral goes un- v heeded. Their minds can not logically reach the conclusion to which the chain of circumstances will drive the normal adult. A little questioning of such persons who attend moving pictures and read stories will indicate how different are the factors which impress their minds, from those which impress the intelligent adult. This failure to grasp the significance of the story is even more pronounced when it is conveyed only by the posters advertising it. Here it seems to be the rule to portray only the most glaring and exciting portion of the plot with no possibility of right interpretation. A survey of any group of posters advertising motion pictures, with only their direct appeal in mind, will show a surprisingly large portion of them suggesting murder, burglary, violence or crime of some sort. The pistol seems to be one of the commonest of the stage properties of the motion picture advertisement. And a very frequent pose is that of the frenzy of rage and the clenched fist ready to strike a blow. Those young people and even adults who are limited to the advertising posters for their entertainment may get evil and anti-social suggestions from them. Considering the almost unlimited audiences which the advertising posters command, their careful control would seem a greater necessity even than that of the play itself. It is just on account of this susceptibility to suggestion that the mentally retarded criminal and the child criminal need a special kind of treatment and special courts to handle their cases. Indeed, much has been done in recent years toward the proper treatment of these two classes of criminals. What needs most emphasis now, however, is 'prevention, not cure. Proper control of their environment is the one factor which will do much to make of these two classes respectable members of society instead of criminals. There are many sources of evil suggestions which can not be eliminated, so long as there are immoral and anti-social persons, and to that extent the atmosphere in which children develop and the feebleminded live, must remain far below the ideal. But that is a good rea |