IN a recent communication, Baker1 directed attention to the difference in size of pistillate and hermaphrodite flowers in gynodiœcious and gynomonœcious plants and suggested that the hormonal control of sex-expression might be connected with the level of auxin activity in the developing flower bud. In the course of genetical studies of gynodiœcy in members of the Labiatae, I have made some observations on the orign of this size difference in the case of Glechoma hederacea L.