NATURE OF ORGANIC REMAINS. BY 
CHAPTER III. 
ON THE NATURE OF FOSSILS, OR ORGANIC REMAINS, 
Fossits ; Perriractions.—It is very generally the case, 
that persons who are not conversant with the nature of 
organic remains, suppose that all fossils are petrifactions ; 
and unless a specimen has the aspect and hardness of stone, 
they regard it as of modern origin, and devoid of interest. 
Hence they are surprised to find among the choicest trea- 
sures in the cabinet of the geologist, shells and corals as 
perfect in form, as if recently collected from the sea-shore ; 
_ bones as little changed, as if they had been interred but for 
a short period ; and teeth possessing their sharp edges and 
enamel unimpaired. In my early researches I fell into this 
error, and threw away many beautiful shells that were 
_ associated with casts of ammonites in the marl at Hamsey, 
supposing, from their perfect state, that they had been acci- 
dentally imbedded, and were not genuine fossils. But the 
state of preservation, and the degree of change which an 
organic body has undergone in the mineral kingdom, have 
no necessary relation to its antiquity. The shells in some of 
the ancient secondary strata are frequently as little changed 
as those in modern tertiary deposits. I have collected from 
the lowermost clays of the Wealden, fresh-water shells with 
traces of the epidermis, and the ligament by which the 
_ valves were held together, perfect ; and bones of reptiles 
from the strata of Tilgate Forest, as light and porous as 
those of the bears and hyenas, from the Caverns of Germany. 
On the other hand, fossil remains from the newest tertiary 
