ABSTRACT
This chapter reviews data bearing on the interplay of the external and internal factors which is so important in the development of the individual organism. It discusses critically some aspects of human heredity. The chapter deals with a discussion of the rise of behavior patterns of the individual. According to geneticists the basic unit or element in heredity is the gene. Genes are minute particles of organic matter lying within the nuclei of the sex and somatic cells. Some of the determinants of structure and function are intrinsic to the protoplasm or cells, and in this sense are at the outset dependent on heredity. The physiological gradient largely determines the fact that the intraindividual environment will be different for the various regions of the body. In the mammals and in man the embryonic and fetal development within the maternal body represents the end product of the evolutionary pattern of standardized environment.
