| Because the egg is retained and fertilized within the archegonium, the early stages of the developing sporophyte are protected and nourished by the gametophytic tissue. |
| An archegonium consists of neck cells and a large egg cell. |
| When the sporophyte has developed all three regions, the seta elongates, pushing its way out of the archegonium and rupturing it. |
| The axis of the embryo is inclined to that of the archegonium and may be almost at right angles. |
| The archegonium has the form of a narrow flask with a long neck. |
| The fertilized nucleus or germ-cell of the archegonium in Cryptogams, from which the new plant is directly developed. |
