vi PREFACE. 
Natural History,” September, 1855. Reprinted with- 
out alteration of the text. 
IL—Own toe Texpency or Varieties TO DEPART 
INDEFINITELY FROM THE ORIGINAL TYPE.. 
First published in the “Journal of the Proceedings 
of the Linnean Society,” August, 1858, Reprinted 
without alteration of the text, except one or two 
grammatical emendations. 
JIL.—Mimicry AND OTHER PRorectivE RESEMBLANCES 
AmonG ANIMALS. 
First published in the “‘ Westminster Review,” July, 
1867. Reprinted with a few corrections and some 
important additions, among which I may especially 
mention Mr. Jenner Weir’s observations and experi- 
ments on the colours of the caterpillars eaten or 
rejected by birds. 
IV.—Tse Matayan Paprinionip#, orn SwALLow- 
TarteD BUTTERFLIES, AS ILLUSTRATIVE OF THE 
Tuzory or Natura SELECTION. 
First published in the “ Transactions of the Lin- 
nxan Society,” Vol. XXV. (read March, 1864), under 
the title, “On the Phenomena of Variation and Geo- 
graphical Distribution, as illustrated by the Papilionide 
of the Malayan Region.” 
The introductory part of this essay is now reprinted, 
omitting tables, references to plates, &c., with some ad- 
ditions, and several corrections. Owing to the publi- 
