The fertilized egg-cell (oospore) forms a filamentous structure, the proernbryo, from a restricted basal portion of which one or more embryos develop, one only as a rule reaching maturity.
Submerged leaves are usually filamentous or narrowly ribbonshaped, thus exposing a large amount of surface to the water, some of the dissolved gases of which they must absorb, and into which they must also excrete certain gases.
As division proceeds, the filamentous nature of this cytoplasm becomes more prominent and the threads begin either to converge towards the poles of the nucleus, to form a bipolar spindle, or may converge towards, or radiate from, several different points, to form a multipolar spindle.
The cock has a fine yellow bill and a head bearing a rounded crest of filamentous feathers; lanceolate scapulars overhang the wings, and from the rump spring the long flowing plumes which are so characteristic of the species, and were so highly prized by the natives before the Spanish conquest that no one was allowed to kill the bird when taken, but only to divest it of its feathers, which were to be worn by the chiefs alone.
In the hen the bill is black, the crest more round and not filamentous, the uropygials scarcely elongated, and the vent only scarlet.