Transcriber's Notes:
Missing punctuation, including periods, hyphens, and commas, has been added.
Obvious typographical errors have been corrected.
Variations in spelling have been left as in the original in the following words:
| coveredst | coverest |
| orang-otang | orang-outang |
| water-skin | waterskin |
The spelling of the last name of Scottish astronomer John Pringle Nichol has been corrected throughout the text.
The spelling of the last name of French naturalist Jean-Baptiste Lamarck has been corrected throughout the text.
The spelling of the last name of French physicist Claude-Servais-Mathias Pouillet has been corrected throughout the text.
The spelling of the last name of Hellenistic astrologer Vettius Valens has been corrected throughout the text.
The spelling of the last name of French mathematician Urbain Jean Joseph Le Verrier has been corrected throughout the text.
A series of three asterisks * * * represents an ellipsis in the text. Shorter and longer rows of asterisks have been standardized to three asterisks.
Footnote 15 reads "Origin of Species, 4, 10, 127, 9, 97, 100, 409, 410, 415, 423. Descent of Man, 192, 204, and II.—15, 257." The page number "9" is probably a typographical error, but it has been left as in the original.