The Stolen Bacillus and Other Incidents - A collection of stories. In plain text (two versions) or as a zip file, from Project Gutenberg. - http://www.gutenberg.org/etext/12750
Literature Network: In the Days of the Comet - Chapter indexed HTML of the complete text. Includes a search feature and an author biography. - http://www.online-literature.com/wellshg/days_comet/
University of Virginia: The Door in the Wall and Other Stories - Unindexed HTML of the complete text. Includes some illustrations. - http://etext.lib.virginia.edu/etcbin/browse-mixed-new?id=WelWall&tag=public&images=images/modeng&data=/texts/english/modeng/parsed
Literature Network: The Door in the Wall - Unindexed HTML of the complete text. Includes a search feature and author biography. - http://www.online-literature.com/wellshg/5/