If the parent or parents then living, or, if they both be not living, if any two of his adult kin within the third degree shall unite with the minor and his next friend in his application, or if the minor has no parent then living and no kindred within the prescribed degree whose place of residence is known to him or his next friend, it shall not be necessary to make any person defendant thereto. But the court shall proceed to investigate the merits of such application, and decree thereon as in other cases.
In cases where a minor has been adopted by decree of court, the adoptive parent or parents, or the next of kin of the adoptive parent or parents, as the case may be, may unite with the minor and his next friend in his application in lieu of the natural parents or the next of kin of the natural parents, as herein provided. Where the custody and control of a minor has been by decree of court awarded to one of the natural parents or adopted parents, as the case may be, to the exclusion of the other, it shall be sufficient herein for only the parent to whom the custody and control has been awarded to unite with the minor and his next friend in his application, as herein provided.