Human sperm diluted in buffer imaged at room temperature within two hours of ejaculation. Cell at center swims at constant speed.

Figure 426 (A-D) from Chapter 16 (Cytoplasmic matrix and cytoskeleton) of 'The Cell, 2nd Ed.' by Don W. Fawcett M.D. Stages of differentiation of the finch spermatozoon. A.)Early in spermatogenesis,...

The movie shows, in real time, the explosive acrosomal reaction of Thyone (sea cucumber) sperm. The field shows several sperm heads (bright contrast) with tails of some in the plane of focus. From the...

Figs. 315 from Don Fawcett's Chapter 12 (Centrioles). The dense material that forms the capitulum and the cross-striated columns of the connecting piece in spermatozoa is formed in intimate associatio...

Figure 421 from Chapter 16 (Cytoplasmic matrix and cytoskeleton) of 'The Cell, 2nd Ed.' by Don W. Fawcett M.D. Horizontal section through the apical cytoplasm of a Sertoli cell in the testis of the t...

A confocal micrograph of a human embryo, with some remaining sperm cells, about five days after fertilization. The nuclei of both the sperm and cells of the embryo are stained purple, the tails of the...

Light micrograph of human ovum (egg) and sperm. The ovum is much larger than the sperm and is surrounded by protective cumulus cells around the outside surface (yellow). The membrane surrounding the o...

Figures 347 (upper) and 348 (lower) from Chapter 14 (Sperm Flagellum) of 'The Cell, 2nd Ed.' by Don W. Fawcett M.D. Sperm tail organization in some insects deviates from the organization observed in ...

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...

Figure 337 from Chapter 14 (Sperm Flagellum) of 'The Cell, 2nd Ed.' by Don W. Fawcett M.D. A transverse section through a portion of a sperm bundle of the newt, Notophthalmos viridescens at the level...