CONTENTS. 



CHAPTER IV. 



THE PRESERVATION OF PLANTS AS FOSSILS. 



Pp. 54—92. 



Old surface-soils. Fossil wood. Conditions of fossilisation. Drifting 

 of trees. Meaning of the term ' Fossil.' Incrustations. Casts of 

 trees. Fossil casts. Plants and coal. Fossils in half-relief. Petrified 

 trees. Petrified wood. Preservation of tissues. Coal-balls. Fossil 

 nuclei. Fossil plants in volcanic ash. Conditions of preservation. 



CHAPTER V. 



DIFFICULTIES AND SOURCES OF ERROR IN THE 

 DETERMINATION OF FOSSIL PLANTS. Pp. 93—109. 



External resemblance. Venation characters. Decorticated stems. 

 Imperfect casts. Mineral deposits simulating plants. Traces of 

 wood-borers in petrified tissue. Photography and illustration. 



CHAPTER VI. 



NOMENCLATURE. Pp. 110—115. 



Rules for nomenclature. The rule of priority. Terminology and con- 

 venience. 



