in Australia.'] 



INTRODUCTORY ESSAY. 



Tropics 



, South-west 



, South-east. 



South-east 



, South-west 



, Tropics. 



Tropics 



, South-east 



, South-west. 



South-west 



, South-east 



, Tropics. 



Tropics 



, South-east 



, South-west. 



South-east 



, South-west 



, Tropics. 



South-west 



, South-east 



, Tropics. 



Tropics 



, South-east 



, South-west 



South-east 



, South-west 



, Tropics. 



Tropics 



, South-west 



South-east. 



. 15. Verbenaceae has most species in the Tropics ; next, South-west ; fewest in the South-east. 



16. Loganiaceae 



17. Cruciferse 



18. Loranthaceae 



19. Lobeliacese 



20. TJrtieese 



21. Ranunculaceae 



22. Polygaleae 



23. Solanese 



24. Lentibularinese 



25. Boragineae 



The sequence in this case is wholly inverted from what obtained in A and B, and we have — 



Fourteen twenty-fifths attaining their maximum in the Tropics. 

 Six twenty-fiftha „ „ South-east. 



Eive twenty-fifths „ „ South-west. 



This accumulation of ordinal and generic peculiarity of Australian vegetation in the south-west 

 quarter of the continent, as compared with the south-east especially, is a very remarkable feature ; 

 it would still have been very striking had there been any contrasting peculiarity of climate or surface 

 between these districts, which is not the case. 



An examination of the proportions which the largest Natural Orders bear to the whole Flora 

 affords very important data for determining the relations of a Flora. I find that half the Australian 

 species are included under the following Orders, which I have here arranged nearly in the order 

 of their numerical extent, and contrasted them with those of some other countries. 





Australia. 



India. 



South Africa. 



Europe. 



World. 



1. 



2. 

 3. 



Le^uminosaa. 



Myrtacese. 



Proteaceae. 



Leguminosae. 



Rubiacese. 



Orchideae 



Compositse. 



Leguminosse. 



Ericeae. 



Compositse. 



Leguminosse. 



Cruciferae. 



Compositse. 



Leguminosae. 



Gramineae. 



4. 

 5. 



Composite. 

 Gramineae. 



Compositae. 

 G-ramineae. 



Gramineae. 

 Liliaceae. 



Gramineae. 

 Umbelliferse. 



Orchideae. 

 Eubiacese. 



6. 

 7. 

 8. 

 9. 



Cyperaceae. 

 Epacrideae. 

 Goodeniaceae. 

 Orchideae. 



Euphorbiaceae. 

 Acanthaceae. 

 Cyperacese. 

 Lahlatffi. 



Iridese. 

 Diosmeae. 

 Scrophularineaj. 

 Geraniaeeae. 



Caryophylleae. 

 Scrophularineae. 

 Labiata?. 

 Ranunculaceae. 



ffl 



Hence it appears, that of the nine Natural Orders which together include upwards of half the 

 known Australian Flowering Plants, three Orders are similarly characteristic of all the other areas 

 compared, two of three areas, and two of two areas. In other words, — 



Compositae, Leguminosae, and Gramineae, are found in all five areas. 

 Cyperaceae and Orchideae, in three. 

 Epacrideae (Ericeae) and Myrtacese, in two. 

 Goodeniaceae and Proteaceae, in Australia alone. 



Rude as the above data and methods of comparison are, they appear clearly to corroborate the 



/2 



