22O 



N, M. STEVENS. 



3 



--/- x 



8 



FIGS. 1-2. Mctaphasc of first maturation mitosis, showing i8+A' and i8+X 

 + 25. (Mag. 1,500 for all figures.) 



FIGS. 3-5. Mctaphase and anaphascs showing position of X. 



FIGS. 60 and b. Young sister spermatocytes of the second order. 



FIGS. 7-12. Variations in position and division of the two supernumeraries 

 in first spermatocytes. 



