Why is there a blank space where a journal issue should be?

So you found a missing volume or issue in our coverage of a journal and you're feeling upset:

We promise we're trying to fix it. You see, JSTOR relies on a number of sources to support our goal of online access to a complete back run. Publishers provide issues they have available and we make every reasonable effort to acquire any missing issues through purchases from third-party vendors. However, in some instances there are still issues gone and in these cases libraries, societies, and individuals have been invaluable in helping to complete journal back runs through donations and loans.

We very much appreciate the generosity of libraries and other sources willing to donate and/or lend needed materials for digitization. If you are in a position to help, or have any questions about a particular issue that you believe is missing, please write to issues.needed@jstor.org.