The divisions of the tail are hard to see, but the really interesting thing about this slide is the shape of the heads. This shape is characteristic of sperm from all of the rodents of which I am aware. To see an example of rat sperm, you can either find a rat or you can click here. Take your pick. Horses have sperm with heads shaped like broadhead arrows, as do humans.
Dogs have paddle shaped sperm heads.
The shapes presumably reflect some sort of structural adaptation to the challenges faced by a sperm in its quest, but why there should be so much species variation is anybody's guess. Accessory Glands of the Male Reproductive System Sperm are merely one component of the ejaculate, and the male accessory glands produce the rest. In histological sections, most of these look much alike. Of these glands, by far the most important to clinicians is the prostate gland . The gland itself takes the form of secretory regions disposed radially around the urethra.