228 GEOLOGY [Chap. IX 



Letter 561 If you look over my Geological Instructions 1 you will be 

 amused to see that I urge attention to several points which 

 you have elaborately discussed. I lately read a paper 

 of yours on Chambers' book, and was interested by it. I 

 really believe the facts of the order described by Chambers, 

 in S. America, which I have described in my Geolog. volume. 

 This leads me to ask you (as I cannot doubt that you 

 will have much geological weight in N. America) to look 

 to a discussion at p. 135 in that volume on the importance 

 of subsidence to the formation of deposits, which are to last 

 to a distant age. This view strikes me as of some importance. 



When I meet a very good-natured man I have that degree 

 of badness of disposition in me that 1 always endeavour 

 to take advantage of him ; therefore I am going to mention 

 some desiderata, which if you can supply I shall be very 

 grateful, but if not no answer will be required. 



Thank you for your Conspectus Crust., 2 but I am sorry 

 to say I am not worthy of it, though I have always thought 

 the Crustacea a beautiful subject. 



Letter 562 To C. Lyell. 



[Down, March 9th, 1850.] 



I am uncommonly much obliged to you for your address, 3 

 which I had not expected to see so soon, and which I have 

 read with great interest. I do not know whether you spent 

 much time over it, but it strikes me as extra well arranged 

 and written — done in the most artistic manner, to use an ex- 

 pression which I particularly hate. Though I am necessarily 

 pretty well familiar with your ideas from your conversation 

 and books, yet the whole had an original freshness to me. I 

 am glad that you broke through the routine of the President's 

 addresses, but I should be sorry if others did. Your criticisms 



1 A Manual of Scientific Enquiry, prepared for the use of Her 

 Majesty's Navy, and adapted for Travellers in General. Edited by Sir 

 John F. W. Herschel, Bart. London, 1849 (Sect. VI., Geology. By 

 Charles Darwin). 



2 Conspectus Crustaccorum in orbis terrarum circumnavigatione, C. 

 Wilkes duce, collectorum. Cambridge (U.S.A.), 1847. 



3 Anniversary Address of the President, Quart. Journ. Geol. Soc, 

 Vol. VI., p. 32, 1850. 



