i88 THE FIRST PRINCIPLES OF HEREDITY 



Dioecious (Gr. di, twice; oikos, house), having the two sex-organs 

 upon distinct individuals (p. 22). 



Ectoderm (Gr. ektos, outside; derma, skin), the external layer of the 



embryo (p. 48). 

 Embryo, embryonic (Gr. embryon), the young organism in its 



earliest stages of development. 

 Embryogenesis (Gr. embryo, genesis, generation), the development of 



the embryo. 



Encyst (Gr. en, in ; kystis, bladder), to become enclosed in a cyst. 

 Endosperm (Gr. endon, within; sperma, seed), the albumen of a 



plant-seed. 

 Entoderm (Gr. entos, within ; derma, skin), the internal germinal 



layer of the embryo (p. 48). 



Epigenesis (Gr. epi, upon ; genesis, generation) (p. 77). 

 Epithelium (Gr. epi, upon ; thele, nipple), the cell-tissue forming the 



outer and inner lining of the body. 



Eugenics (Gr. eu, well ; genes, producing), good breeding (p. 181). 

 Eutechnics (Gr. eu, well; techne, art), good arts, industries (p. 182). 

 Eutopia (Gr. eu, well ; topos, place), good surroundings (p. 182). 

 Evolutio (L. e, out ; volvere, to roll), an unfolding (p. 77). 

 Evolution (L. e, out ; volvere, to roll), the doctrine according to 



which the higher forms have evolved from the lower. 



Fertilization (L. fertilis, fertile), the process of fertilizing (p. 42). 

 Filial (L. filius, a son), pertaining to a son or daughter. 

 Fission (L. ftndere, to cleave), a kind of division (p. 12). 

 Foetus, foetal (L. feuere, to bring forth), the animal in the womb in 

 its later stages. 



Gamete, gametic (Gr. gamos, marriage), the sexual germ (p. 124). 



Gastrula (Gr. gaster, belly) (p. 47). 



Gemmule (L. gemma, bud), a little bud (p. 54). 



Genetic, genetical (L. generare, to generate), pertaining to generation. 



Geotropism (Gr. ge, earth ; tropos, a turn), the tendency to growth 



downwards. 



Germinal (L. germinare, to bud), pertaining to the germ. 

 Germ-plasm (L. germen, a bud ; Gr. plasma, form) (p. 58). 



Haemophilia (Gr. haima, blood ; philia, love), a constitutional 



tendency to bleeding (p. 113). 

 Heliotropism (Gr. helios, sun ; tropos, a turn), the tendency to growth 



towards the sun. 



