FIG. 29. Shows cross-sections of elongating nebenkern; _a_ shows axial filament, nebenkern and acrosome; in _b_ the axial filament is cut at an angle.
FIG. 30. A little later than fig. 28; the axial filament not so plainly shown.
FIG. 31. The ring has disappeared, and the dark mass is passing down along the filament. The acrosome is indistinct.
FIG. 32. The nebenkern has disappeared, but the acrosome has kept its position.
FIG. 33. The acrosome has flattened against the nucleus. Some remains of the nebenkern are seen.
FIG. 34. The acrosome has moved to the side of the nucleus. Some nebenkern remains are shown.
FIG. 35. The acrosome is in front of the nucleus.
FIG. 36. A little later stage than fig. 35.
FIG. 37. Shows a divided acrosome. It is not a frequent appearance.
FIG. 38. The nebenkern appears as a hanging drop on the side of the axial filament.
FIG. 39. The nucleus has condensed, the walls have thickened, and the chromatin appears in granules. The acrosome is pointed.
FIG. 42. The head is stained intensely, while the acrosome is lighter. Probably a middle piece indicated.
FIG. 44. Cross-sections of the head, of the stage shown in fig. 43.
FIG. 45. The head and part of the tail of a mature spermatozoon.
End of the Project Gutenberg EBook of The Kansas University Science Bulletin, Vol. I, No. 2, Febr, by W. J. Baumgartner