1. Where the public utilities commission has authorized a motor bus operation but neglected at the time to make a formal order- or to issue the certificate, such hearing and determination constitutes the exercise of administrative -discretion and the formal order can be entered at a later daté. The omission to issue the certificate does not avoid the proceedings and the ministerial act of such issuance can likewise be performed at a later date.

2. Alleged irregularities and technical defects in the proceedings for the authorization and issuance of a certificate of convenience and necessity for a motor bus operation cannot be challenged by a protestant in a hearing for transfer of such certificate but must be brought to the attention of the commission in a separate proceeding upon complaint filed and five *157days notice thereof to the holder of such certificate and hearing thereon.

Order affirmed.