The townships now in existence and those to be created after this act takes effect are divided into two classes, townships of the first class and townships of the second class. Townships of the first class are those having a population of at least three hundred inhabitants to the square mile, which are now established as townships of the first class, or which may be created townships of the first class under laws relating to townships of the first class. All townships that are not townships of the first class or home rule townships are townships of the second class. A change from one class to the other shall be made only under this act or the laws relating to townships of the first class.
53 P.S. § 65201