Geological Society of London. 91 
distribution of fossil vegetables from the study of undisturbed dis- 
tricts. You are not ignorant that the strata of the Alps are involved 
in extreme confusion 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 
several thousand feet of beds belonging to an older formation. So 
obscure is the order of position in Alpine geology, that the creta- 
ceous and greensand series have been classed by experienced geolo- 
gists as more ancient than the oolite, under which, in point of fact, 
they occasionally lie. 
Prof. Studer, in his work on the Bernese Highlands, after years 
of personal investigation, has published a map in which he has given 
a colored ground plan without venturing to commit himself by sec- 
tions, 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 classifi- 
cation 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 | related to him some geological phenomena which 
surprised him; ‘I believe it,” he said, ‘“‘ because you have see it, 
but had | 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 Prof. Sedg- 
wick have endeavored, and I think successfully, to work a great re- 
form in the classification of the ancient rocks of that country, by ap- 
plying to them the arrangement which they had previously made for 
the deposits termed by rag and Lower Silurian in Wales 
and the adjoining parts of England. According to their survey and 
sections, the coal plants of Bideford, so far from constituting any 
anomaly, so far from affording any objection to the doctrine that par- 
ticular species of fossil plants are good tests of the relative age of 
rocks, do in reality from the place which they occupy, confirm that 
