Antheridium

Antheridium, an organ of various form and position in different groups of cryptogamic plants, analogous to the anther in flowering plants. In most cases it bursts and discharges minute protoplasmic bodies, furnished with cilia, which are known as antherosoids. These swim about in water and ultimately fertilise the germ-cell. They thus represent the contents of the pollen-tube in flowering plants.