archegonium's Usage Examples:

Each commences its existence as a simple naked protoplast, in the embroyo-sac or the archegonium, as the case may be.

No other substance, at least, with which he experimented had a like effect, and it is possible that in the archegonium which contains the ovum malic acid is present.

When the archegonium has opened by the separation of the terminal cells of the neck, the disintegration of the canal cells leaves a tubular passage, at the base of which is the ovum (fig.

A, Unopened archegonium; o, ovum; ventral canal cell; k', nec k-canal-cell.

The Bryophyta and Pteridophyta have sprung from the higher Thallophyta, and together form the larger group Archegoniatae, so-called from the form of the organ (archegonium) in which the egg-cell is developed.

In the former the prothallus produces one or more fern-plants vegetatively, the projection which develops into the sporophyte in many cases occupying the position of an archegonium.

An archegonium consists of a large oval egg-cell surmounted by a short neck composed of one or more tiers of cells, six to eight cells in each tier.

B, Mature opened archegonium.

The archegonium (fig.

archegonium, those surrounding the archegonia and base of the seta.

Important points of difference exist, however, in the apical position of the meristem of the Ophioglossaceous prothalli, in the presence of a basal cell to the archegonium, and in the multiciliate spermatozoids.