434 E - L - SHAFFER. 



EXPLANATION OF PLATE IV. 



FIG. 29. Formation of first maturation spindle; the mitochondria are at one 

 side and are beginning to envelop the spindle. 



FIG. 30. Metaphases of first maturation division; the mitochondria com- 

 pletely surround the spindle. 



FIGS. 32, 33, 34. Cross-sections of the first maturation spindle, showing its 

 relation to the mitochondria. 



FIG. 35. Late anaphases of the first maturation division; the mitochondria 

 are densely staining and closely applied to the spindle. The mitochondria do not 

 reach to the poles. 



FIG. 36. Second spermatocyte; interkinesis. Mitochondria in a dense mass 

 awaiting the formation of the second maturation spindle. 



FIG. 37. Second maturation spindle forming with the mitochondria at one side. 



FIG. 38. Young spermatid with deeply staining Nebenkern (TV) lying close to 

 the nucleus, and the spindle derivative (5) which contains a deeply staining cor- 

 puscle. Centrosome not clearly in focus. 



FIG. 39. Later stage in spermatid transformation, showing the elongation of 

 the Xebenkern after the axial filament has grown out. 



