10 TEXT-BOOK OF EMBRYOLOGY. 



pigment. These few examples are sufficient to indicate that cytoplasmic 

 organization of the ovum determines in a measure the course of development 

 of the future embryo. 



References for Further Study. 



CONKLIN, E. G.: Heredity and Environment in the Development of Men. 1920. 



KEIBEL, F. and MALL, F. P.: Manual of Human Embryology. Vol. I, Chap. I, 1910. 



KELLICOTT, W. E.: Text-book of General Embryology. Chap. Ill, 1913. 



WALDEYER, W.: In Hertwig's Handbuch der vergleichenden und experimentellen 

 Entwickelungslehre der Wirbeltiere. Bd. I, Teil I, Kap. I, 1906. Contains extensive 

 bibliography. 



WILSON, E. B.: The Cell in Development and Inheritance. 2d Ed., 1900. 



