Oogonia and oospores of the Water Mould - Saprolegnia

In Saprolegnia the tip of a non-septate hypha swells up, becomes filled with dense protoplasm, and is cut off by a wall from the hypha that produces it to form a spherical OOGONIUM.    Spherical EGGS cleave from the protoplasm and these become fertilized to produce thick-walled OOSPORES (resting spores) that are eventually released by break down of the wall of the oogonium.   The oospores can persist through adverse conditions (heat - cold - dry) for years until such times as the conidions are again favourable for renewing their growth cycle.