ABSTRACT
The practical problem of evolution consists in regulating biological heredity as far as possible, and then in trying to produce conditions that will enable social heredity to act to the best advantage. The higher centres and the association fibres are developed late in the child; they are likewise the latest acquirements of the race. As the child grows older, the spine becomes less flexible and more rigid with increased power in the spinal muscles. A lower death-rate always predicates less sickness and more vigorous vitality in the infants who live. While deaths among older babies have decreased, the number of infant deaths during the first month has not lessened, but at times has even increased, which shows that the pre-natal and natal periods have not been equally watched. The infant and little child has always offered the best approach to a study of both medical and social problems.
