Rejuvenation.-War accidents resulting in asexualization with attendant loss of masculine traits and of personality and acumen led to physiological experimentation. Rejuvenation and acceleration of puberty in animal subjects: Experimentation on animal subjects shows deterioration due to asexualization and a more than corresponding revival when glands are again grafted in, after any length of time, whether in the normal location or elsewhere. By an incision senile subjects are revived and take on

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... all the traits of youth in physical appearance, behavior, and procreative powers. The effect is heightened if healthy glands of other individuals are grafted in. Extent of rejuvenation: By these operations rejuvenation is effected to the extent of one-fourth the life-expectancy of the animal subject, and can be repeated with similar effect. By the use of Roentgen rays puberty symptoms are produced at one-third the normal age. Rejuvenation of human subjects: The possibility of this has been demonstrated by ingrafting and by an incision where glands were remaining.-Dr. Paul Kammerer, Neue Generation, I6:293-96. E. T. H. Comparative Studies of the Work Process.-The work process as represented in spontaneous expression of maximum exertion is studied by means of measuring devices in not only normal and subnormal persons of different ages, but also in insects, fowls, hares, cats, dogs, and other animals. General type of energy development: Energy is applied in one of two curve forms: spurts of exertion and steady continuous pull. The form of exertion depends on the type of locomotion and on the momentary excitation within the organism. Acute and chronic fatigue: In all subjects the curve flattens with increase of fatigue, distinguishing acute and chronic fatigue. The chronicfatigued have the characteristics of the sensory, non-motor type; the vigorous, nonfatigued have the characteristics of the motor-reaction type. Disposition to exertion: The following among other subjects show themselves capable of near maximum exertion by inner impulse: normal persons, some subnormals, the cat, dog, and possibly even insects. The animal subjects that are not given to exertion out of inner motive are those that readily assume temporary immobility (animal hypnosis). This is overcome by appropriate excitation. Life-principle in terms of exertion: It seems to be a principle common to all life-forms to exert approximately maximum energy by inner movement; where lacking, this is due to peculiar characteristics of the subject concerned. Fatigue causes the subject to misinterpret the objective facts. Rhythm of the work process: Normal adults, some children, and some subnormals show a distinct work rhythm. Where lacking, effort tends to introduce it, thus implying efficacy of practice. Insects exhibit such rhythm, mammals less so. The habituated and intellectually controlled movements and the instinctive movements agree in working in the shortest line to their aim.-J. S. Szymanski, Zeitschriftfiir angewandte Psychologie, i8, I, 3 :I-I8. E. T. H. The Problem of Population.-Popular reaction to Malthus' essay on population: In this treatise Malthus indicated that the permanent improvement of society is impossible without a conscious limitation of the rate at which children are born. His doctrine was attacked by theologians who argued that children were sent by God and that it was impious to interfere with God's decree, and by semisocialists like Godwine who assumed that the limitation of population was a device of the rich to stave off a revolt of the poor. The positive checks on population: Three propositions are set forth This content downloaded from 138.025.078.025 on July 26, 2016 23:38:16 PM All use subject to University of Chicago Press Terms and Conditions (http://www.journals.uchicago.edu/t-and-c). THE AMERICAN JOURNAL OF SOCIOLOGY in the doctrine; namely, population is limited by the means of subsistence; population invariably increases, unless prevented by powerful and obvious checks; these checks are all resolvable into moral restraint, vice, and misery. Population tends to increase pari passu with an increase in the means of subsistence. The races and nations of the world are in the ultimate resort compelled to struggle with one another to get a maximum share of a limited food supply. Limitation of birth-rate: A race limits its numbers by discouraging births-mankind's historic method which still is maintained by lower races and lower classes of people; and by encouraging unwanted babies to die, as in the slums of London and New York. Some highly civilized nations have already learnt to limit their numbers. The lower races must also learn to restrict their numbers, or else the mastery of the world will pass to the inferior but more prolific types of mankind.-Harold Cox, The Dial, May, I92I. C. N. The Agricultural Limits of Our Population.-The law of population: Pearl and Reed have developed a law which is expressed by a portion of the curve of a logarithmic beax parabola having the formula y=l -ceax' where a, b, and c have positive values. The major asymptote of the curve, as applied to our own country, gives the ultimate population limit of continental United States as 197 millions. Making allowances for all other factors, 8oo million acres of arable land will support 320 million people, or 2.5 acres per man. If II millions be added to the preceding sum, which is obtained by calculating the productivity of our grazing lands and forests, the maximum population the United States can support is 321 millions. Land cultivation in other countries: The figures obtained from different countries are comparable with 42 per cent proposed for the United States as the sum total of her arable possibilities. Before the war Germany cultivated 1.15 acres per capita, France i.5 acres, Italy o.g8 acres, Belgium 0.57 acres. China has about 3o0 millions with a land area 600 million acres greater than the United States. Japan, with a population of 52 millions in i9ii, cultivated i8 million acres out of a total land area of 94 million acres. By an extraordinary use of fertilizers she was able to support 3 persons per acre. If the United States could do as well on her 8oo million acres of arable land, our population would be 2,000 millions. But Japan really would need 1.5 acres per man to support her population in terms of American food habits. At this rate the United States could support only 530 millions on her arable land-the ultimate limit humanly possible for the country.-E. M. East, The Scientific Monthly, June, 1921. C. N. La Tyrannie Eugenistique.-Sterilization laws in the United States: Dr. Harry H. Laughlin in the October number of Social Hygiene cites fifteen states in which laws have been passed providing means for the prevention of procreation by defectives confined in state institutions. Such laws put people at the mercy of surgeons and the directors of the institutions without recourse to any tribunal. In five of the fifteen states the law has been declared unconstitutional. A standard state law: Dr. Laughlin advocates a uniform law which would provide for the sterilization of the feeble-minded, the insane, certain types of criminals, epileptics, drunkards, those having certain diseases, the blind, the deaf, the deformed, and dependents. This legislation would be contrary to the principles of equality of the American democracy.-N. Mondet, Journal des economistes, January, 1921. M. S. E. L'Hygiene et l'Education des Enfants Vicieux ou Coupables.-Causes of juvenile delinquency: Heredity and environment are both important factors. Fifty per cent of delinquency is due to lack of proper home life, 30 per cent to mental troubles. Types of delinquent children: (i) the child mentally and morally sound, but exposed to bad environment; (2) the poorly trained child; (3) the mistreated child; (4) the feeble-minded child; (5) the degenerate child; (6) the mentally unbalanced child; (7) the child lacking most of the social instincts. Treatment of delinquent children; (i) Treatment should fit the individual case. To secure this, observation clinics should be established. (2) Juvenile courts should be created. (3) Institutions for the education and guidance of delinquents should be developed. Observation clinics. The problem of finding a suitable place to confine minors while awaiting trial is solved by the observation clinic, in which the mental, physical, and moral life of the child is studied. The changed environment and the treatment by specialists often bring to