220 GEOLOGY [Chap. IX 



Letter 555 plants must have grown in very marine marshes. 1 Do you 

 remember how savage you were long years ago at my 

 broaching such a conjecture ? 



Letter 556 To L. Horner. 



Down [1846?]. 



I am truly pleased at your approval of my book 2 : it was 

 very kind of you taking the trouble to tell me so. I long 

 hesitated whether I would publish it or not, and now that I 

 have done so at a good cost of trouble, it is indeed highly 

 satisfactory to think that my labour has not been quite 

 thrown away. 



I entirely acquiesce in your criticism on my calling the 

 Pampean formation " recent " 3 ; Pleistocene would have been 

 far better. I object, however, altogether on principle (whether 

 I have always followed my principle is another question) 

 to designate any epoch after man. It breaks through all 

 principles of classification to take one mammifer as an 

 epoch. And this is presupposing we know something of 

 the introduction of man : how few years ago all beds earlier 

 than the Pleistocene were characterised as being before the 

 monkey epoch. It appears to me that it may often be con- 

 venient to speak of an Historical or Human deposit in the 

 same way as we speak of an Elephant bed, but that to apply 

 it to an epoch is unsound. 



I have expressed myself very ill, and I am not very sure 

 that my notions are very clear on this subject, except that I 

 know that I have often been made wroth (even by Lyell) at 

 the confidence with which people speak of the introduction of 



1 " On the Origin of Coal," by E. W. Binney, Mem. Lit. Phil. Soc. 

 Manchcste?', Vol. VIII., 184S, p. 148. Binney examines the evidence on 

 which dry land has been inferred to exist during the formation of the 

 Coal Measures, and comes to the conclusion that the land was covered 

 by water, confirming Brongniart's opinion that Sigillaria was an aquatic 

 plant. He believes the Sigillaria "grew in water, on the deposits where 

 it is now discovered, and that it is the plant which in a great measure 

 contributed to the formation of our valuable beds of coal." {Loc. cit., 



P- I93-) 



2 Geological Observations on South America, London, 1846. 



3 " We must, therefore, conclude that the Pampean formation belongs, 

 in the ordinary geological sense of the word, to the Recent Period." 

 {Geol. Obs., p. 101). 



