CONTENTS OF VOLUME IV. 



I. Observations introductory to Vol. Fourth. 



Pronunciation of Cyb-el-e, etc. etc. .... 



PAOE 



II. On Orders, Genera, and Species, 



1. What are Orders and Genera ? 



2. What is a Species ? 



3. Uncertainty of Species . 



4. Inequality of Species 



5. Permanence of Species . 



15 

 27 

 35 

 44 

 52 



III. On the Introduced Species. 



1. Definitions, Opinions, etc 



2. Examples in illustration of introduced Species 



3. Views of Prof. Alphonse De Caudolle 



4. Views of English Botanists . . . , 



5. Views of Dr. Godron, in France 



6. Statistical bearings of introduced Species 



65 

 71 



107 

 120 

 122 



IV. Physical Geography and Climate of Britain. 



1. Geographical position .... 



2. Extent and Area 



3. Division into Counties .... 



4. Division into Provinces and Sub-provinces 



5. Latitudinal Divisions .... 

 G. Longitudinal Divisions .... 



126 

 128 

 129 

 131 

 134 

 136 



