58 THE COMING [CH. 



taking advantage of riding on horseback, and he 

 declared in his letters that he l never had a better 

 man to work with than Murchison'; nevertheless he 

 ridiculed his ' keep-mo ving-go-it-if-it-kills-you ' system 

 as quoting from the elder Matthews he called it 48 . 



On parting from Murchison and his wife, after the 

 Auvergne tour, Lyell proceeded to Italy and for more 

 than a year he was busy studying the Tertiary 

 deposits of Lombardy, the Roman states, Naples 

 and Sicily, and conferring with the Italian geologists 

 and conchologists. Thus it came about that he was 

 not free to resume the task of seeing the Principles 

 through the press till February 1829. 



Immediately after his return to England Lyell 

 was compelled, with the assistance of his companion 

 Murchison, to defend their conclusions concerning 

 the excavations of valleys by rivers from a deter- 

 mined attack of Conybeare, who was backed up 

 by Buckland and Greenough ; the old geologists 

 endeavoured to prove that the river Thames had 

 never had any part in the work of forming its 

 valley 49 . It is interesting to find that, on this 

 occasion, Sedgwick, who was in the chair, was so 

 far influenced by the arguments brought forward 

 by the young men, as to leud some aid to those who 

 had come to be called the ' Fluvialists,' in contra- 

 distinction to the ' Diluvialists ' ; he went so far as to 

 suggest that, with regard to the floods which the 



