If a book has one appendix, it is The Appendix
. Now consider a book with three appendices (or, if you like, appendixes), named Appendix A
, Appendix B
, and Appendix C
. The part of the book, which is formed by these, is called
- still
The Appendix
, because it is that part of the book, composed of the "chapters"Appendix A
,Appendix B
, andAppendix C
. - now
The Appendices
(or, if you like,The appendixes
), because there are three of them and that calls for a plural. - something else (what)?