308 GEOLOGY. 



Primitive Rocks. 



Geologists having found that a certain class of 

 rocks contain no animal or vegetable remains, term 

 them primitive, or primary, as having in their opi- 

 nion been formed before the organic kingdom was 

 called into existence. 



Transition Rocks. 



Upon the primitive rest another class, called by 

 Werner transition rocks, because he supposed them 

 to have been created when the world was passing 

 from an uninhabited to an inhabited condition, and 

 because they contain petrifactions and zoophytes 

 which do not now exist. No remains of vertebrose 

 animals have been detected. 



Floetz Rocks. 



Upon the transition rocks lies another and more 

 numerous class, called jloetz rocks. Of these the 

 older enclose the remains of animals, which not be- 

 ing found now, are supposed to be extinct. The 

 newer of this class contain the remains of animals 

 which approach to, but are not actually the same as, 

 those that inhabit the present seas. The still more 

 recent of the floetz rocks, as well as the alluvial for- 

 mation incumbent on them, contain the remains of 

 animals not to be distinguished from those now exist- 

 ing. The latter also encloses the remains of large 

 land animals. No human remains have hitherto 

 been discovered among extraneous fossils in any so- 

 lid rock, which is not decidedly, both in respect to 

 situation and composition, of very late date. 



Extinct Beings. 



The varieties in the characters of the extinct beings 

 .are not capriciously distributed, but correspond to- 

 lerably distinctly with the order of their position, 



