I06 GARDINER. 



DESCRIPTION OF PLATE X. 



All figures on this plate except Fig. 26 are enlarged 11 40 diameters. 



Fig. 14. First polar spindle leaving the nucleus. 



Fig. 15. Sperm aster forming between the pronuclei. 



Fig. 16. First polar spindle near the surface of the ovum. 



Fig. 17. First polar body just formed. 



Fig. 18. Regenerating nucleus after the first polar has been formed. 



Fig. 19. (a) First polar body, {h) Regenerating nucleus. 



Fig. 20. Female pronucleus regenerating after formation of the second polar 

 body. 



Fig. 21. Anaphase of first polar spindle. ' 



Fig. 22. First polar spindle showing centrosomes. (The boundaries of the 

 asters are drawn distinctly. No such lines exist in nature.) 



Fig. 23. Spermatozoon shortly after it has entered the ovum. 



Fig. 24. Spermatozoon somewhat nearer the center of the ovum. 



Fig. 25. Spermatozoon still nearer the center of the ovum. 



Fig. 26. Diagram of ovum in which the first cleavage spindle appears like 

 a translucent dumb-bell-shaped structure ; P. the two polar bodies ; A A, first 

 plane of cleavage ; BB, line of second plane of cleavage. 



Fig. 27. Polar bodies in the cytoplasmic network of first cleavage spindle. 



