2 INTEODUCTIOX. 



My work is now (1859) nearly finished ; but as it will 

 take me many more years to complete it, and as my 

 health is far from strong, I have been nrged to publish 

 this Abstract. I have more especially been induced 

 to do this, as Mr. Wallace, who is now studying the 

 natural history of the Malay archipelago, has arrived 

 at almost exactly the same general conclusions that 

 I have on the origin of species. In 1858 he sent me 

 a memoir on this subject, with a request that I would 

 forward it to Sir Charles Lyell, who sent it to the 

 Linnean Society, and it is published in the third 

 volume of the Journal of that Society. Sir C. Lyell 

 and Dr. Hooker, who both knew of my work — the 

 latter having read my sketch of 1844 — honoured me 

 by thinking it advisable to publish, with Mr. Wallace's 

 excellent memoir, some brief extracts from my manu- 

 scripts. 



This Abstract, which I now publish, must necessarily 

 be imperfect. I cannot here give references and au- 

 thorities for my several statements ; and I must trust 

 to the reader reposing some confidence in my accuracy. 

 No doubt errors will have crept in, though I hope I 

 have always been cautious in trusting to good authorities 

 alone. I can here give only the general conclusions 

 at which I have arrived, with a few facts in illustration, 

 but which, I hope, in most cases will suffice. ISTo one 

 can feel more sensible than I do of the necessity of 

 hereafter publishing in detail all the facts, with refer- 

 ences, on winch my conclusions have been grounded ; 

 and I hope in a future work to do this. For I am 

 well aware that scarcely a single point is discussed in 

 this volume on which facts cannot be adduced, often 

 apparently leading to conclusions directly opposite to 



