The points which we have brought out in this paper are: 1. The development of the acrosome from the Golgi apparatus, which has been figured for the first time during growth, and the stages of acrosome formation in the human.
2. The almost complete break-up of the Golgi apparatus at dictyokinesis, and the late reassembly of the fragments apparently independently of the spermatid centrioles.
3. The very probable presence of a neck granule apparatus as distinct from the head or proximal centriole (c1).
4. The claim that the head centriole does not divide. The emergence of the flagellum from the proximal and distal centrioles jointly.
5. The development of the post-nuclear cap in human spermatids.
6. The apparent absence of any form of spiral body in the middle-piece.
7. The different types of Golgi apparatus in the Sertoli and spermatogenic cells.
8. The presence of a vacuole in the head of the spermatozoon.
9. The remarkable ‘nutrient syncytium’ connected with the Sertoli cells.
10. The accessory body in the cytoplasm.