Transcriber-added descriptions of some illustrations are in parentheses, like this: [Illustration: (description)]. Some words were printed both with and without accent marks. The ones clearly meant to be the same (e.g., Index references to the other form) were changed; the rest appear both ways. Greek and symbols not in the Latin-1 or ASCII character sets have been transliterated or substituted in those versions of this eBook. The original letters and symbols might appear in the UTF-8 and HTML versions. Devices unable to display such characters may substitute question marks or other placeholders.