The flattering reception of my Essays by the public and the press having led to a second edition being called for within a year of its first publication, I have taken the opportunity to make a few necessary corrections. I have also added a few passages to the 6th and 7th Essays, and have given two notes, explanatory of some portions of the last chapter which appear to have been not always understood. These additions are as follows:-- +-------------------------------------------------------------------+ | _To avoid altering the paging the additional pages now given have | | been lettered._ | +---------+---------+-----------------------------------------------+ | 1st Ed. | 2nd Ed. | | +---------+---------+ | | 221 | 221 | Additional facts as to birds acquiring | | | | the song of other species. | | | | | | 223 | 223A } | Mr. Spruce's remarks on young birds | | | 223B } | pairing with old. | | | | | | 228 | 228A } | Pouchet's observations on a change | | | 228B } | in the nests of swallows. | | | | | | 229 | -- | Passage omitted about nest of Golden | | | | Crested Warbler, which had been | | | | inserted on Rennie's authority, but | | | | has not been confirmed by any later | | | | observers. | | | | | | 261 | 261 | Daines Barrington, on importance of | | | | protection to the female bird. | | | | | | | 372 | Note A. | | | | | | | 372B | Note B. | +---------+---------+-----------------------------------------------+ CONTENTS. I.--_On the Law which has regulated the introduction of New Species._ Pp. 1-25 Geographical distribution dependent on Geologic Changes A Law deduced from well-known Geographical and Geological facts The form of a true system of Classification determined by this Law Geographical Distribution of Organisms Geological Distribution of the forms of Life High Organization of very ancient Animals consistent with this Law