495 



me remind you that botanists have been led to very different con- 

 clusions respecting«the laws governing the distribution of fossil ve- 

 getables from the study of undisturbed districts. You are not 

 ignorant that the strata of the Alps are involved in extreme confu- 

 sion and complexity, mountain masses having been completely 

 overturned and twisted, so that the same set of strata have been 

 found at the top and bottom of the same section separated by seve- 

 ral thousand feet of beds belonging to an older formation. So 

 obscure is the order of position in Alpine geology, that the cretaceous 

 and greensand series have been classed by experienced geologists 

 as more ancient than the oolite, under which, in point of fact, they 

 occasionally lie. 



Professor Studer, in his work on the Bernese Highlands, after 

 years of personal investigation, has published a map in which he 

 has given a coloured ground plan without venturing to commit him- 

 self by sections, or a table of the regular order of superposition. 



After devoting a summer to the investigation of the same portion 

 of Switzerland, with the advantage of Mr. Studer's map and work, 

 I was unable to satisfy myself that I had found a key to the classi- 

 fication or superposition of the formations, so enormous is the scale 

 on which they have been deranged. I collected fossil plants on the 

 Col de Balme, but I have not examined the precise localities further 

 to the west appealed to by M. de Beaumont. I am far, therefore, 

 from denying his facts or inferences, hoping at some future period 

 more carefully to inquire into the evidence on the spot. No one, I 

 am aware, is more desirous that others should visit the southern 

 Alps and verify or criticise his facts than M. de Beaumont. Mean- 

 while I am reminded of an expression of our mutual friend M. von 

 Buch. When I related to him some geological phsenomena which 

 surprised him ; " I believe it," he said, " because you have seen 

 it, but had I only seen it myself, I should not have believed it." 



But to conclude, and to recall your attention to the structure of 

 Devonshire, you will perceive that Mr. Murchison and Professor 

 Sedgwick have endeavoured, and I think successfully, to work a 

 great reform in the classification of the ancient rocks of that 

 country, by applying to them the arrangement which they had pre- 

 viously made for the deposits termed by them Cambrian and Lower. 

 Silurian in Wales and the adjoining parts of England. According 



