SPERMATOGENESIS OF LITHOBIUS FORFICATUS

Summary. 1. The spermatogonium is a somewhat spindle‐shaped cell with granular mitochondria and a few curved Golgi rods. 2. During the growth phase a spermatogonium enlarges into a giant egg‐like spermatocyte. 3. Each spermatocyte contains granular mitochondria, a large number of highly curved Golgi elements and curious cytoplasmic fibres which at times attain huge dimensions. Each Golgi rod may have a distinct archoplasmic sphere associated with it. 4. In a centrifuged spermatocyte the cytoplasmic fibres are thrown at one end but the mitochondria and the Golgi elements remain uniformly scattered. 5. The cytoplasmic fibres are well preserved with Mann‐Kopsch and chromeosmium. They are destroyed to a large extent by fixatives containing acetic acid. Hence all the earlier workers do not figure them. 6. The “metaplasm” and the “formations ergastoplasmiques” of Blackman and Bouin brothers respectively are really the Golgi elements which are not completely destroyed by acetic acid. 7. During meiosis the mitochondria and the Golgi elements are distributed into two sub‐equal parts. 8. When the spermatid is formed most of the Golgi rods assume the form of rings. 9. All the mitochondria and the Golgi elements go into the tail of the sperm and directly form the tail sheath. 10. The acrosome is probably secreted by a few Golgi rings which get stuck to the anterior face of the nuclear membrane of the maturing sperm. It is very prominent in the ripe sperm. 11. A few small granules constantly occur on that portion of the nuclear membrane of the maturing sperm from which the axial filament starts. They are intensely blackened with omit acid and are very probably of the Golgi origin.