A lamella of granular endoplasmic reticulum was found to be associated with the outer surface of the Golgi apparatus of golden hamster spermatids during the period of acrosome production. The morphological situation during this period has some features in common with those reported in other cell types during the production of secretory granules, including lysosomes. Thus, the observations are compatible with the view that the acrosome is a specialized lysosome.
Stacked lamellae which resemble annulate lamellae were also found to be associated with the Golgi apparatus of some spermatids. The morphological variations observed are consistent with the possibility that annulate lamellae may in some cases undergo conversion into granular endoplasmic reticulum.