_(e) Diminution of Natality._—There is no more certain sign of the degeneration of a race, nation, or class than a decreasing birth-rate. When it reaches the point that the deaths in its ranks exceed the births, extinction has already begun. Providing that fecundity continues normal, the onslaughts of war, famine, and pestilence may be remedied; but when, through agencies of any description, the birth-rate sensibly falls off, there is no escape from destruction. This disaster may arise from physical, but is generally due to psychical causes, and therefore points distinctly to mental pathology in the group where it occurs. Striking examples of this have been presented by studies of the noble families of Europe. Placed in positions where their chief aims were amusement, self-indulgence, and ostentation, their best faculties were allowed to rust and finally to decay, bringing with this the extinction of their lines. Researches in European history show that the ennobled families of France, Germany, and England have rarely survived the fifth generation, and not more than six per cent. are in existence after three hundred years. Of 427 English noble families, but 41 were represented at the beginning of the 17th century. The patrician families who controlled the free cities of the Middle Ages are now known in history only. Scarcely a score have outlived the degenerative agencies of wealth, idleness, and indulgence. The other extreme of the social scale is equally unfriendly to productiveness. It is popularly thought that the poor man has children if he has nothing else. But he must not be too poor. Surgeons of the Indian civil service have proved by ample statistics that the famines which periodically ravage the East bring in their train widespread and lasting infertility. Arrest of puberty and organic deterioration of the reproductive system are common results of the prolonged starvation, and prevent child-bearing. The psychic contrast between this result and that of malignant epidemics is marked and singular. During and after famines the feelings dependent on sex are almost extinguished; while in epidemics of acute diseases, such as plague, cholera, and yellow fever, they are notably exalted, as they are also in leprosy. There is also a class of maladies known in medicine as “dystrophic” on account of their tendency to diminish virility, and thus both lessen the birth rate and lead to morbid psychic states. Prominent among these are malarial fevers, tuberculosis, and the later stages of alcoholism and the opium habit. By many writers the inordinate use of tobacco is believed to exert a similar effect.