In 14 cases of the Turner syndrome and pure gonadal dysgenesis streak gonads were studied histologically. In cases where the 46,XX line was unimpaired the blood vessels of the gonad showed severe degeneration in at least 30 to 50%. These streak gonads usually contained some of the characteristic ovarian elements as well as the vascular lesions. In gonosomal monosomy, on the other hand, a simila...