Where anything herein is required or permitted to be done by the state road commissioner, the same may be done in person or by superintendents, agents, or employees of the state road commissioner, upon his authority duly given, and he may set up a department of prison labor having charge of the agencies and persons under his authority as herein provided for, and account for the operations of the state convict road force therein; but in any event such accounts and operations shall be separately stated.