The upper ribs possessing the signs of both cervical and first ribs (such as the size, conjunction with the sternum, dilatation of the superior intercostal spaces, double width and others) are the intermediate forms. Small dimension fluorography of 400.000 humans with roentgenographical control has revealed 468 persons with transitional forms of cervical and first ribs (0,12%), i. e. one case per 800 humans at an average. Transitional forms of cervical and first ribs can be grouped as follows: asymmetry of clavicles, asymmetry of the upper ribs, close position of the upper ribs, double width of the first ribs, conjunction of the cervical and first ribs at the vertebrum.