The nuclear membrane then disappears and Fibrillar cell-plasma or cytoplasm invades the nuclear area.
"Darwin and Modern Science"
A.C. Seward and Others
The exposed posterior part of each bears posteriorly converging ridges; the anterior part is widest and shows a fine Fibrillar structure.
"A New Genus of Pennsylvania Fish (Crossoperygii, Coelacanthiformes) from Kansas"
Joan Echols