From the hereditary standpoint, color and size characters in either plants or animals are not equally well understood. In general, the inheritance of color, technically known as a qualitative character, has been rather satisfactorily determined. On the modern chromosome theory of heredity, the genetic factors responsible for the development of colors appear to be located on the various chromosomes of the species and apparently follow a regular, stable and predictable mode of inheritance from generation to generation. Environmental agencies play a relatively minor part in ;modifying such characters. It is for this reason, perhaps, that their inheritance has been so thoroly investigated.