Occurrence of nuage in fetal human germ cells.

Germ cells of human fetuses aged 7-13 weeks were studied. Dense fibrous material called nuage was found in the cytoplasm of human fetal germ cells. The nuage increased in frequency in the germ cells during the interval studied. In oogonia the nuage occurred much more frequently than in spermatogonia and the frequency of nuage in oogonia increased earlier than in spermatogonia. The number of nuage was continuously at a higher level in oogonia than in spermatogonia. It is suggested that these findings support the theory that the nuage may act as a germ cell determinant.