INSULAR FLORAS. 375 



else. The predominating natural orders of vascular plants 

 occupy nearly the same positions numerically in both islands ; 

 ferns being first and orchids second, and Leguminosae and 

 Compositae relatively low down ; very different proportions 

 from those obtaining in the Madagascar Mora, in which 

 these four orders occupy reversed positions. Thus : Legu- 

 minosae, Filices, and Compositae, followed by the Orchideae, 

 which are represented by just half as many species as the 

 Leguminosae. 



The absence of a number of natural orders from Dr. 

 Cordemoy's Flora that are represented in Mauritius may 

 be accounted for partly by the fact that he did not work out 

 the old collections made before the destruction of the virgin 

 forests which formerly clothed the island. It is probable 

 that many species have disappeared from both islands from 

 the same cause. The following orders known to be, or as 

 having been, represented in Mauritius are not included by 

 Cordemoy : Xyridaceae, Scitamineae, Podostemaceae, Myo- 

 porineae, Bignoniaceae, Lentibulariaceae, Gentianaceae, 

 Rhizophoreae, Connaraceae, Simarubaceae, Ochnaceae, Bur- 

 seraceae and Nymphaeaceae. The absence of several of the 

 foregoing orders might be accounted for without calling in the 

 theory of destruction, but it would lead too far to attempt the 

 discussion of the matter here. Myoporum mauritianum is 

 an instance of a plant, and an order that is no longer repre- 

 sented, if it ever were ; for there may have been an error 

 in locality. The only specimen at Kew is labelled as coming 

 from one small patch at the east end of the island of 

 Rodriguez, which is some 300 miles distant from Mauritius. 

 Moreover the Seychelles and Rodriguez between them 

 possess several natural orders which do not reach Bourbon 

 or Mauritius, though they are represented in Madagascar. 

 They are Nepenthaceae, Passifloraceae, Turneraceae, Diptero- 

 carpeae (?), Ternstrcemiaceae and Dilleniaceae ; whereof the 

 first and the fourth are essentially Asiatic, the second 

 and third American, and the two last equally Asiatic 

 and American. The parasitical Rafflesiaceae are perhaps 

 the only natural order in Bourbon that is not repre- 

 sented in Mauritius. Cordemoy records Hydnora afncana 



