Vlll HEREDITY AND SELECTION IN SOCIOLOGY 



PAGES 



some in matured egg — This regression can be prevented by arti- 

 ficial means — Experiments of Tichomiroff, Loeb, and Petrun- 

 kewitsch. 

 3. Weismann's theory of the germ-plasm— The continuity of 

 the germ-plasm — Active and inactive germ-plasm — Active 

 germ-plasm is adapted to the needs of the ontogeny, inactive 

 germ-plasm to the needs of the phylogeny — The germ-plasm is 

 located in the chromosomes — Structure of the germ-plasm : ids, 

 determinants, biophors — ^The " germinal tract " — ^Function of 

 the determinants — Homodynamio and heterodynamic deter- 

 minants — Integral and differential division of the determinants 

 — Active and passive determinants — -Liberation of determinants 

 during the embryogenesis — Vital affinities — ^Histological deter- 

 mination of the cell — Struggle of the parts within the organism ; 

 theory of Wilhelm Boux — ^The number of determinants — Sum- 

 ming-up 11-40 



CHAPTER ni 



Geeminai. Selection 



1. Preformation of the organism in the germ — Heterogeneity of the 



germ-plasm — ^The determinants are autonomous living particles 

 in definite developmental relation to given parts of the finished 

 organism — The modification of the determinants entails corre- 

 sponding modification of these parts. 



2. Germinal selection — Force of the objections formerly raised 



against the original theory of the ancestral plasm — ^These 

 objections now answered by the theory of germinal selection — 

 The original source of variations — Elementary particles of the 

 germ-plasm demand and receive nourishment — The biophors 

 are capable of assimilation and growth — The strength of the 

 determinants depends on the available quantity of nourishment, 

 and on the assimilatory capacity of the determinants — Amphi- 

 mixis mingles the heterogeneous ids — Quantitative and quali- 

 tative differences increase in proportion to the number of de- 

 terminants — Heterogeneous determinants and the influence 

 exercised by homogeneous environing conditions — Regression of 

 the determinants — Source of all hereditary variation to be found 

 in shiftings of the balance among the determinants — Action of 

 natural selection on germinal variations — Limitation of ascendant 

 variations — lUimited character of regressive variations — ^Re- 

 gression of useless organs — Role of amphimixis in germinal selec- 

 tion — The reducing divisions and germinal selection — Correlation 



