These two novels by Lewis Carroll differ from his other fiction in a number of ways in addition to having their own indexes. Each of them, for example, is several times as long as either of the Alice books; but more importantly, the Sylvie and Bruno books were written with a moral—something studiously avoided in the Alice books and almost all of Carroll's other fiction written during his adult years.... Sadly, when the Sylvie and Bruno books have been reprinted in those one-volume tomes purporting to be 'The Complete Works of Lewis Carroll', the indexes to Sylvie and Bruno are regularly omitted. The publishers either do not appreciate their importance and novelty, or, more likely, do not wish to incur the expense of adjusting the page references.

In at least one of his works, Sylvie and Bruno, Lewis Carroll showed that he had mastered the art of indexing, Victorian style. The first part of the work was published in 1889 by Macmillan in London and had an index whose whimsicality perfectly fitted the equally whimsical text, though it occupied only five of the book's 400 pages. Four years later, there appeared Sylvie and Bruno concluded, and this time, Carroll provided it with a 'General index' of 21 pages which included most of the entries for volume I as well as entries for volume II.