The material part of the section runs thus: (1) No suit shall be instituted against the Corporation or against the Commissioner, or the 188 Transport Manager, or against any municipal officer or servant in respect of any act done or purported to be done in pursuance or execu tion or intended execution of this Act or in respect of any alleged neglect or default in the execution of this Act: (a) until the expiration of one month next after notice in writing has been, in the case of the Corporation, left at the chief municipal office and, in the case of the Commissioner or of the Transport Manager or of a municipal officer or servant delivered to him or left at his office or place of abode, stating with reasonable particularity the cause of action and the name and place of abode of the intending plaintiff and of his attorney, advocate, pleader or agent, if any, for the purpose of such suit, or (b) unless it is commenced within six months next after the accrual of the cause of action.