In reply to Nick Huffman, it depends whether he is asking about the "chapter headings" or the introduction to the chapters -- the "Chapter I" and onward were drawn by E. W. Kemble and sometimes incorporated into the initial letter. Some of the "chapter headings, on the other hand, were written by Twain as were some of the captions for the illustrations. For the introductions to the chapters, when the illustrations were deleted, the format changed for the various editions. As for the "chapter headings," some of them are very interesting and add a bit of humor to the chapter. Check some of them in the reproduced first edition done by Oxford University Press. I hope this answers some of the questions.