Geology. : 275 
' 22. It isa great thought, that throughout the incaleulably long succes- 
sion of fossiliferous deposits, palaeozoic or more modern, all animal and 
vegetable life was constructed upon the same idea of innervation, organs 
sense, supply and waste, fecundation, &e. 
23, There is another kind of life-centre—the geographic, belonging to 
one and thesame group. This forms numerous separate provinces linked 
together by a few common fossils, and displaying extraordinary variety. 
This principle or revulation is carried out abundantly everywhere. Bohe- 
mia and Scandinavia have scarcely a Silurian fossil in common. 
ee ar. Even the east and west sides of the small 
districts in Wales and England investigated by Prof. Philips, differ re- 
markably in their population. We see this in the American Tertiaries 
and in the recent seas. 
24. Contrary to the opinion of Mr. D. Sharpe, the molluse having the 
greatest vertical range has the greatest horizontal extension, being foun 
in the most distant regions, : 
25. here is no evidence of multiplication of species by transmutation. 
tions, such as temperature, depth, currents, &c., which were nowhere 
here 
tions were making for Lower Silurian deposits,—there for the 
pi or Devonian, and so on. Thus isochronism was perhaps not 
mon 
27, The principles of recurrency, succession, increment, and relative 
abundance of foesil species are - gpets in New York, Wales, and else- 
tances. . : 
ce in different strata, is at the same time 
the measure of viability in the species and of connexion in the groups of 
Strata. It is a kind of living nexus, pointing out that the groups belong 
— and the same order of things. It may have been partly caused 
igration, ; 
urrency is not so common in New York as in Wales,—in. other 
ge vertical range is longer in Wales. Great depth is an obstacle to 
®xistence or transmission of living creatures. 
Matting of fucoids, appear at what now seems ‘to be the ‘ ¢ 
then some Gaston 2 a hee Cephalopoda, and a few Brachiopoda in 
up from below (Chazy). But in the fe group fro 
"yOZ0a, Brach opoda 
