Abstract: | The ovarian cortex of chicken embryos of 10 to 14 days of incubation was observed in order to study the formation of the primary tunica albuginea and to discern in its cells an ultrastructural confirmation of an eventual steroidogenic capacity which has been proposed by some authors. From observations at the electron microscope, it is probable that the mesenchyme-like cells which constitute the primary tunica albuginea may originate from the somatic cells of the cortex, either from those of the germinal epithelium, or from those which, because of their position, may be termed prefollicular. There is not apparent ultrastructural confirmation of an active steroidogenic capacity in the albugineal cells. A possible physiological difference between clear cells and dark cells due to a different electron density, is furthermore discussed. |