CHAPTER XIV

Heredity and Germinal Continuity--Mendel. Galton. Weismann, 305

The hereditary substance and the bearers of heredity, 305. The nature of inheritance, 305. Darwin's theory of pangenesis, 306. The theory of pangens replaced by that of germinal continuity, 307. Exposition of the theory of germinal continuity, 308. The law of cell-succession, 309. _Omnis cellula e cellula_, 309. The continuity of hereditary substance, 309. Early writers, 310. Weismann, 310. Germ-cells and body cells, 310. The hereditary substance is the germ-plasm, 311. It embodies all the past history of protoplasm, 311. The more precise investigation of the material basis of inheritance, 311. The nucleus of cells, 311. The chromosomes, 312. The fertilized ovum, the starting-point of new organisms, 313. Behavior of the nucleus during division, 313. The mixture of parental qualities in the chromosomes, 313. Prelocalized areas in the protoplasm of the egg, 314. The inheritance of acquired characteristics, 314. The application of statistical methods and experiments to the study of heredity, 314. Mendel's important discovery of alternative inheritance, 316. Francis Galton, 317. Carl Pearson, 318. Experiments on inheritance, 318.