Abstract
The regeneration of the mouse adrenal gland was studied after enucleation and transplantation with the object of determining whether, or not, a, new X-zone will develop. In a small % of operated animals dark cortical cells were found towards the central part of the gland resembling X-zone cells but in no single instance did a distinct X-zone regenerate. Although it cannot be stated that X-zone cells do not develop there is no definitive regenerated area such as occurs (see authors'' previous reports) following pregnancy in the [female] and cessation of androgen adm. in the castrate [male].