Appointments of reserve police officers shall be made consistent with and pursuant to the provisions of this article as hereinabove described, upon the recommendation of the chief of police to the Police Commission. All reserve police officers shall serve a probationary period of six (6) months. Reserve police officers may be discharged at any time, for any cause, by the chief of police. All Police Department insignia, identification and property, is required to be returned by the reserve police officer to the department immediately upon discharge.