Punctuation, hyphenation, and spelling were made consistent when a predominant preference was found in this book; otherwise they were not changed. Simple typographical errors were corrected; occasional unbalanced quotation marks were corrected. Ambiguous hyphens at the ends of lines were retained. “Errata” at the end of Volume II have been applied to the relevant text of this eBook. This is Volume I of a two-volume set. The Table of Contents for both volumes is in this one. This Volume I ends on page 400, so references to pages 401-729 will be found in Volume II. The Index for both volumes is in Volume II. Footnotes and references to them have been renumbered into one continuous sequence and moved to the end of this eBook. Some footnotes are referenced several times. Some “See note” references may be incorrect. Reading devices that cannot display some of the characters in this eBook may substitute question marks or other placeholders. Page 137: “lunules, 1 had 3, 1 had 3, and a 4th” was printed that way. Page 142: “of the 10 females 8 were changed” was misprinted as “7 were”, which was an arithmetic error; corrected here. Page 151: “No change was observed” was printed as “charge”; changed here. Volume II is available at no charge from Project Gutenberg, www.gutenberg.org, as eBook number 44444. An eBook combining both volumes is available as eBook number 55555. End of the Project Gutenberg EBook of Studies in the Theory of Descent, Volume I (of 2), by August Weismann