132 EVOLUTION [Chap. Ill 



Letter 86 To L. Horner. 1 



Down, Dec. 23rd [1859]. 

 I must have the pleasure of thanking you for your 

 extremely kind letter. I am very much pleased that you 

 approve of my book, and that you arc going to pay me the 

 extraordinary compliment of reading it twice. I fear that it 

 is tough reading, but it is beyond my powers to make the 

 subject clearer. Lycll would have done it admirably. 



You must enjoy being a gentleman at your ease, and I 

 hear that you have returned with ardour to work at the 

 Geological Society. We hope in the course of the winter to 

 persuade Mrs. Horner and yourself and daughters to pay us 

 a visit, llkley did me extraordinary good during the latter 

 part of my stay and during my first week at home ; but I 

 have gone back latterly to my bad ways, and fear I shall 

 never be decently well and strong. 



P.S. — When an}' of your party write to Mildenhall I 

 should be much obliged if you would say to Bunbury that 

 I hope he will not forget, whenever he reads my book, his 

 promise to let me know what he thinks about it ; for his 

 knowledge is so great and accurate that every one must 

 value his opinions highly. I shall be quite contented if his 

 belief in the immutability of species is at all staggered. 



Letter 87 To C. Lycll. 



In the Origin of Species a section of Chapter X. re devoted to "The 

 succession of the same types within the same areas, during the late 

 Tertiary period " (Ed. I., p. 339). Mr. Darwin wrote as follows: "Mr. 

 Clift many years ago showed that the fossil mammals from the Australian 

 caves were closely allied to the living marsupials of that continent." 

 After citing other instances illustrating the same agreement between 

 fossil and recent types, Mr. Darwin continues : " I was so much impressed 

 with these facts that I strongly insisted, in 1839 and 1845, on this 'law of 

 the succession of types,' on ' this wonderful relationship in the same 

 continent between the dead and the living.' Professor Owen has 

 subsequently extended the same generalisation to the mammals of the 

 Old World." 



1 For biographical notes on Horner and Sir C. Bunbury see a letter 

 to Horner, Jan. 1847 (Geology). 



