Hereditary Matter: The Chromosome

Abstract

Increases in depth and breadth of knowledge have resulted from the observation of effects or behavior, at one level, to a search for causes at another. Through breeding experiments using whole organisms, it has been possible to develop laws of inheritance. The causes for these laws must be looked for in the physical makeup of the organism itself, in its cells and molecules. In other words we must shift our level of inquiry from the organism to the cell and its components.