Said school shall be presided over by a superintendent, who shall be a person trained in educational and social work, and said superintendent shall have the power of detention over the children committed thereto. When any child committed to said school shall have attained a condition of mental and moral advancement satisfactory to the superintendent and the board of managers, they shall so certify to the juvenile court which committed said child to said school; whereupon the said court may order the release of said child, upon parole, under conditions which shall be prescribed by said board, by general rule and subject to the approval of the proper juvenile court; and in case the conduct of any child released upon parole shall be such as to satisfy the board of managers that a further period of training and detention is necessary, such board shall certify said fact to the proper juvenile court; and thereupon such court shall have power, at any time during the minority of said child, to direct the apprehension and return of said child to said school, where it shall remain, subject to the same control as when originally committed thereto.
11 P.S. § 377