462 ELMER L. SHAFFER. 



PLATE III. (Fics. 23 TO 33). 



FIGS. 23, 24. Metaphase plates of first sparmatocytes showing characteristic 

 grouping of chromosomes; macrochromosoine tetrad in center surrounded by a 

 circle of autosome tetrads with the sex-chromosome (X) lying outside the group. 



FIGS. 25, 26. Successive sections of same cell. Anaphase of first maturation 

 division showing separation of dyads of the .4.4, BB, CC tetrads. Mitochondria 

 surrounding the spindle. 



FIG. 27. Late anaphase of first maturation division. Sex-chromosome lags 

 behind and appears bipartite; macrochromosome dyads (.4, .4) showing secondary 

 split. Mitochondria are divided by cell-constriction. 



FIG. 28. Daughter plates of second spermatocyte, one with 9 dyads the other 

 with 9 dyads plus the sex-chromosome (X). All the dyads show the secondary 

 split. 



FIG. 29. Late anaphase of the second maturation division. Centrosomes 

 adhere closely to the daughter nuclei; chromatoid body has passed to one of the 

 daughter cells. Mitochondria are divided by the cell constriction. 



FIG. 30. Normal spermatid. Centrosome (c) adheres closely to nuclear 

 membrane. 



FIG. 31. Giant spermatid, with all the structures of a normal spermatid, 

 except that they are much larger. 



FIG. 32. Transformation of the spermatid. Elongation of the Nebenkern 

 pierced by axial filament. Cr., chromatoid body passing out into tail. 



FIG. 33. Stages in spermiogenesis. Elongation of Nebenkern to form sheath 

 around axial filament. 



