A 
FERN PHYTOLITHUS. 
The indisputable remains of animal and vegetable 
bodies, so plentifully dispersed throughout almost 
all parts of the globe, and of which a great many 
are of a widely different appearance from the present 
natives of the regions in which they are found, form 
one of the most interesting points ot speculation in 
the history of nature. 
Various and even contradictory hypotheses have 
occasionally been proposed as elucidations of this 
subject, which yet remains in a considerable degree 
of obscurity ; the true theory of the earth being 
perhaps still but very imperfectly understood. It 
must be allowed, however, that vast and violent 
changes have been wrought in the body of the 
primeval earth ; that we walk as it were on the 
ruins of the original structure ; and that both lire 
and water have united their forces to derange the 
first formation. 
Of these great convulsions of nature, though the 
causes yet remain unexplored by all the endeavours 
of improved philosophy, yet the effects are every 
where visible. 
On the tops of mountains, remotely distant from 
the sea, even on those of the Andes in Peru, are 
found the remains of innumerable marine produc¬ 
tions, both animal and vegetable; many of which are 
• still unknown in their recent state, and are there¬ 
fore 
