Geology and Natural History. 467 
happen to be contrary to the established creed of the dominant 
party. As a general rule, the leading men are right, and yet it 
will sometimes happen that they are wrong. One of the most 
remarkable instances on record is that of the great question in 
American geology, relating to the age of the rocks whic : 
Emmons called “ Taconic System.” Upon this question 
nearly all of the leading geologists of North America arranged 
themselves upon one side, and, as it turned out after more than 
twenty years discussion, on the wrong side, Although they were 
wrong, yet so overwhelming was the weight of their authority, 
that for nearly a quarter of a century Dr. Emmons stood ress 
d 
During the last thirteen years, a great revolution of opinion has 
vi mons. Although not 
is at this moment dead, more so than was the Taconic theory im 
1859, the year in which the subject was reopen s I under- 
Worked out, and judging from the manner in which the strata are 
folded, broken up and thrown out of their original position by 
almost every kind of geological disarrangement, I venture to say 
that no man, at present living, will ever see a perfect map of the 
Taconic re ion. | 
_The theory that the Taconic rocks belonged to the Hudson 
tiver group, was an enormous error, that originated in the 
Geological Survey of New York, and thence found its way Into 
the Canadian Survey. No doubt the mistake was due, in the fi 
instance, to the extraordinary arrangement of the rocks, the more 
ancient strata being elevated and often shoved over the more 
— us, without the aid of paleontology, 1t was Lape 
to assert positively that they were not, what they app to be, 
e of th dson river formation. 
Strata, together with their numerous disturbances, might be ex- 
Plained physically, so as to meet either theory. If, for instance, 
the trilobites of Vienbat and Point Levis had turned out to be of 
