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Gametangia are Embedded in the Dorsal Surface.

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Antheridial Cavity
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The Protrusions in the SEM photo are sites where the Antheridia are breaking through the surface of the Thallus

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Antheridium rupturing the surface of the Thallus

Biflagellate Sperm are produced by the Antheridia.

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Bifalgellate Sperm

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Embedded Archegonia. You can see the openings to the Neck Canals.

The Archegonia are unique and lack a Neck & Venter. (A minor point).

Sporophytes

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Sporophytes at Various Developmental Stages

The Archegonia produce a Calyptra which protects the Sporophyte during early Development. It is translucent at first but later it becomes green.
Sporophyte Development

The Sporophytes are Cylindrical & highly elongate. They grow for a relatively long time and have an
Intercalary Meristem like grasses.

This means that meristematic activity is confined to the base rather than the apex. They are are not exactly Sequoia-like in growth, but they can reach 16 cm in height.

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Diagram showing the relationship between Sporophytes & Gametophytes

Sporogenous Tissue develops in the capsule. The central Columella is sterile and can have cells with spiral secondary wall thickenings. This provides support for the elongated Sporophyte.

The Meiospores are surrounded by several layers of Parenchyma cells and an Epidermis. Stomata are present in the Epidermis.
The Sporophyte has several autotrophic adaptations. remember them!!!!!!

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Cross-Section through the Sporophyte of Anthoceros. Note the Epidermis, Chlorenchyma layers, Spores and Columella.

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