BOTANY OF TERRA AUSTRALIA. 7 



Oxford, tlie greater part of the plants brought from Shark's 

 Bay by the celebrated navigator Dampier, and have seen a 

 few additional species from that and other parts of the 

 West Coast of New Holland, collected in the voyage of 

 Captain Baudin. 



The additional species obtained from all these collections 

 are upwards of 300 ; my materials, therefore, for the com- 

 mencement of a Flora of Terra Australis amount to about 

 4200 species ; a small number certainly for a country 

 neaily equal in size to the whole of Europe, but not incon- 

 siderable for the detached portions of its shores hitherto 

 examined. 



In Persoon's Synopsis, the latest general work on phae- 

 nogamous plants, their number is nearly 21,000. The 

 cryptogamous plants already published, by various authors, 

 exceed GOOO ; and if to these be added the phgenogamous 

 plants that have appeared in different works since the pub- 

 lication of Persoon's Synopsis, and the unpublished species 

 of both classes already existing in the collections of Europe, 

 the number of plants at present known may be estimated 

 at 33,000, even exclusive of those peculiar to Terra Aus- 

 tralis. 



The observations in the present essay being chiefly on 

 extensive tribes of plants, they are necessarily arranged [537 

 according to the natural method. 



Of this method the primary classes are Dicotyledones, 



MONOCOTYLEDONES, and ACOTYLEDONES. 



These three divisions may be admitted as truly natural, 

 and their nauies, though liable to some exceptions, appear 

 to me the least objectionable of any hitherto proposed. 



Of the Australian plants at present known, upwards of 

 2900 are Dicotyledonous; 860 Monocotyledonous ; and 

 400 Acotyledonous, Ferns being considered as such. 



It is well known that Dicotyledonous j)lants greatly 

 exceed Monocotyledonous in number ; I am not however 

 aware that the relative proportions of these two primary 

 divisions have anywhere been given, or that it has been 

 inquired how far they depend on climate. Into this 

 subject I can enter only very generally in the j)rescnt essay. 



