ROOM I. 



CHAPTER I. 

 PART II. FOSSIL YEGETABLES. 



FOSSIL VEGETABLES PETRIFIED VEGETABLES CARBONIZED VEGETABLES 



COAL AMBER JET DIAMOND FUCOIDES ASTEROPHYLLITES EQUI- 



SETACE.E CALAMITES FILICITES SIGILLARIA STIGMARIA ERECT 



SIGILLARIA LYCOPODIACEJE LEPIDODENDRON CARBONIFEROUS FLORA 



PSAROLITES CLATHRARIA ENDOGENITES DRAC^NA FOSSIL PALMS 



NIPATITES CONIFERS CYCADEACE.E ZAMLJ* PETRIFIED FOREST OF 



PORTLAND MANTELLIA FOSSIL TREES OF NEW HOLLAND. 



FOSSIL VEGETABLES. Vegetable remains occur in the 

 mineral kingdom in various states of preservation, and under 

 very different conditions; in some cases, they are but little 

 changed in aspect and composition; in others, they are so 

 completely metamorphosed that their vegetable nature can 

 only be detected by the aid of the microscope. It will suf- 

 fice for our present purpose to consider two principal 

 states in which the fossil remains of trees and plants are 

 preserved. 



1st. Petrified Vegetables : In this state the organic structure 

 is permeated by mineral matter, and oftentimes the original 

 vascular tissues are transmuted into stone : it may be calca- 

 reous, as in some of the fossil woods from the Lias ; or siliceous, 

 as in the wood from New Holland, and the palm-stems from 

 Saxony ; or partly calcareous and partly siliceous, as the trees 

 from the Isle of Portland, &c. Iron is a frequent constituent 

 in the petrifaction of vegetable substances ; and the sulphuret, 

 or iron pyrites, is very constantly present in wood, fruits, 

 leaves, <fec., imbedded in argillaceous deposits ; often impart- 

 ing a most beautiful metallic lustre to the organic structures, 

 as in the fossil fruits from the Isle of Sheppey. 



