The theory of the quota in proportional representation - errata

It is the object of the various systems of proportional representation to secure, in the words of J. S. Mill, that "every or any section shall be represented, not disproportionately, but proportionately." If it is necessary to divide a country into a number of constituencies, the only way to secure proportional representation with certainty is to ensure that in every constituency each party is represented in proportion to the number of its supporters in that constituency. The adoption of any other electoral system must make the representation depend on the accident of the distribution of the parties among the constituencies.
The division of a country into single-member constituencies will usually produce disproportionate representation, even if the member for each constituency is elected by a majority of the voters in the constituency, for the representation of either party will depend on the number of constituencies in which it is in a majority, and this number will not usually be proportionate to the strength of the party throughout the country. Page 48 is Errata.