Embryology of Microphthalmos in Rattus Norvegicus

There are a number of influences which affect and arrest the developing eye in its embryonic growth: for example, mechanical injuries, or abnormal pressures; infections, toxicoses, vitamin or other nutritional deficiencies and metabolic and endocrine disturbances in the mother ante partum, and interference with the blood supply to the embryo or to the developing primordia. Certain abnormalities of the eye have been shown to be inherited. Adelman1reviewed literature by Stockard, Guyer and Smith, Little and Bagg and others on the production of ocular abnormalities by artificial means. Hale2reported the appearance of such abnormalities in litters from sows reported as deficient in vitamin A. Browman3and Cannon4were unable to confirm this finding using vitamin A—deficient rats. The problem of cyclopia (Adelman,1Wright and Wagner5) is not considered to have a direct bearing on the production of microphthalmos in mammals with both eye