Fig. 4. The acrosomal vesicle (Ac V) has spread out over the nucleus 

 (N). Its lumen is narrower and the Golgi complex (Go C) is less 

 closely associated with its surface than in the earlier stage (Fig. 3). 

 The hemispherical acrosomal granule (Ac Gr) is situated at the tip of 



the elongated nucleus. 



Fig. 5. The acrosomal vesicle here extends down over the anterior 



half of the nucleus to form the head cap (C). Its lumen is reduced to a 



narrow cleft and its content is considerably more dense than before. 



The acrosome granule (Ac Gr) is markedly flattened. 



