In the development of Ontario, townships have been reasonably fixed, but Districts and Counties have often changed. A complete list of the townships of Ontario are contained in: Gartner,ME; Prong,CF - Index of Ontario Townships
Information on the surveying of townships and the development of districts and counties is in: Dean, WG; Matthews, GJ - Economic Atlas of Ontario - UofT Press (1969), particularly Plates 98 and 99.
Much of this information comes from RG19-20-1 at OA, a collection of documents concerning the legal existence of townships and municipalities. It seems that pre 1850 there were few laws passed affecting the legal existence of townships, with the result that it is difficult to determine the early history. An attempt was made in 1937 by the Ontario government to gather data from the townships but a lot of it came back “unknown” or “based on the memories of our oldest inhabitants”.