I 62 



N. M. STEVEN-. 



connected by spindle fiber- .1- in I'iv. 2*. This timuv sh<>\\- 

 the larger (.Y) and smaller (vi lieien>ehn>nin- ( i]iu- \\itli Himoth 

 outline, and the remainder <>l tin- rhnmiaiin in the form of 

 irregular clumps and strands. In sonic cases -ec-md spermato- 

 cyte spindles have been found associated with firsi -permatnrytes 



30 



31 



33 



35 



FIG. 28. A pair of second spermatocytes slmwin- tin heterochrom 

 and y. 



FIG. 29. Second spermatocyte metaphase. 



FIG. 30. Second spermatocyte equatorial p; 



FIG. 31. Second spermatocyte anaphase. 



.Pics. 32-35. Four stages in the transformation <>t" tin- spermatid, -li>\viiii; no 

 trace of the hetcrochromosomes. All figures 2,000 X i '^ reduced ' _. 



iii mitosis in such away as to indicate that the rest stai^e betwcrn 

 the two divisions may often be omiited. This is as tar a> the 

 heterochromosomes can be traced. 



In the second maturation spindle I have never been able t<> 

 count the full number of chromo-i-iiu .- because <>!" > roudiii^ and 

 overlapping. In the clearest case- -een in ai rniinc prepa- 



