_The Great Number of Children._--The chief cause of high infant mortality and of high child mortality among the lower strata of the population is the great size of their families. The number of conceptions, pregnancies, and births varies directly as the infantile death-rate. If out of a certain limited income more children have to be maintained, the share of each in the commodities purchasable out of that income necessarily diminishes. The income of the manual worker is so small that, even if his family is quite a small one, it is exceedingly difficult for him to provide out of that income what he and his wife and children need for the satisfaction of elementary vital needs. With every additional child comes a further limitation of supplies for each individual member of the family. Not only does this have a directly unfavourable influence upon health, inasmuch as each child receives a smaller share of dwelling-room, food, &c. In addition, as more and more children are born, the worth of the individual child in the eyes of the parents diminishes. The mother’s health is apt to suffer from the rapid succession of conceptions, pregnancies, and deliveries. For various reasons this is disadvantageous to the children. A woman thus affected will subsequently bring more weakly children into the world; the mother whose health is poor is unable to give as much time and pains to the rearing of her children as she would if she were well and strong; many women whose health has been broken by unduly frequent pregnancies die during a subsequent pregnancy or delivery. But may it not be that the relationship between a large number of births and a high infantile death-rate is the reverse of that which we have suggested? Is it not possible that the great mortality among children may be the cause of an increase in the number of conceptions, pregnancies, and births? It is true that certain purely psychological factors may contribute to such a causal sequence. To a certain degree a high infantile death-rate has such an effect. For if a woman gives birth to a diseased or a still-born child, or if one of her children dies, the parents are more likely than would otherwise be the case to desire to have another child, and the wife will be more ready to undertake the troubles of another pregnancy and the risks of another delivery.