This electron micrograph shows a cross section through the midpiece of opossum sperm. Filamentous cytoplasm underlies a scalloped membrane with regular variations in thickness, which gives it a corrug...

Transmission electron micrograph of unstained cryo-section of a sperm cell of the starfish Patiria miniata. Echinoderm sperm nuclei are unusual in that chromatin fibers are clearly seen, allowing the...

Figures 342 (upper) and 343 (lower) from Chapter 14 (Sperm Flagellum) of 'The Cell, 2nd Ed.' by Don W. Fawcett M.D. Cross sections of spermatozoa from the caddis fly (Polycentropus, upper) and mosqui...

Transmission electron micrograph of unstained cryo-section of a sperm cell of the starfish Patiria miniata. Echinoderm sperm nuclei are unusual in that chromatin fibers are clearly seen, allowing the...

Scanning electron micrograph showing in vitro fertilization of a hamster oocyte. The sperm head, near the center of the field of view, is engulfed by the microvilli on the surface of the oocyte membr...

Scanning electron micrograph showing a lateral view of sperm penetration of a hamster oocyte during vitro fertilization. As the membrane of the sperm head fuses with that of the oocyte, the microvill...

Figure 346 from Chapter 14 (Sperm Flagellum) of 'The Cell, 2nd Ed.' by Don W. Fawcett M.D. Top panel: A cross section of sperm tail of the cecidomyid fly, Diplolaboncus tumorificus shows mitochondria...

Transmission electron micrograph of unstained cryo-section of a sperm cell of the starfish Patiria miniata. Echinoderm sperm nuclei are unusual in that chromatin fibers are clearly seen, allowing the...

Cross section through a seminiferous tubule showing the developing sperm with their tails pointing into the lumen of the tubule. The nuclei are stained blue with DAPI and mitochondria red with mitotra...

Figure 329 from Chapter 14 (Sperm Flagellum) of 'The Cell, 2nd Ed.' by Don W. Fawcett M.D. This electron micrograph shows a transverse section through the midpiece of Chinese hamster spermatozoa. Im...