Transcriber's Note
Page 235 has been corrected to 239 in the Illustration index.
Punctuation errors were corrected.
The following printer's suspected spelling errors have been addressed.
Page 91 alterative changed to alternative
as an alternative than food
Page 111 ancedote changed to anecdote
than the following anecdote
Page 129 narrrowing changed to narrowing
and narrowing towards the end