The Effect of a Deficiency of the Antiscorbutic Factor in Guinea-Pigs and of the Fat-Soluble a in Rats**Read before the Section on Histology, Physiology, Pathology, Bacteriology and Chemistry (Research) at the Sixty-Seventh Annual Session of the American Dental Association, Louisville, Ky., Sept. 22, 1925.This constitutes a part of the work which has been carried out under grants from the American Dental Association, the Forsyth Dental Infirmary, Harvard University and the Massachusetts Dental Society.