INTRODUCTORY ESSAY. 51 



been incorporated into De Candolle's Systema. These^ and 

 his Florula of the Island of Hongkong, in ' Hooker's Journal 

 of Botany/ connect his name most intimately with the pro- 

 gress of Indian botany ; it is however impossible here to indi- 

 cate the long list of memoirs he has pubhshed, and which 

 more or less bear upon the subjects discussed in this Essay. 



Since the date of publication of Wight and Arnott's Pro- 

 dromus, the great work of De CandoUe, the ' Prodromus Sy- 

 stematis Regni Vegetabilium/ has advanced from the fourth 

 to the thirteenth volume ; and as the rich materials for the 

 Indian Floraj especially those collected by Wallichj were com- 

 municated to its author, the Prodromus contains a very 

 complete resume of our knowledge of Indian botany up to the 

 period of publication of each natural order. This materially 

 facilitates the study of the CorolUflorous Orders, the most 

 important of which have been worked up by Mr. Bentham. 

 With regard to the Thalamifiorous and Calyciflorous Orders 

 previous to Compositse, these, with the exception of the Penin- 

 sular ones, have for the most part to be worked out ab initio 

 for the Flora Indicaj the earlier volumes of the Prodromus 

 being to a great extent compilations, and particularly defective 

 in all that regards the vegetation of Asia. 



Next in point of botanical importance comes Dr. Eoyle's 

 ' Illustrations of the Botany of the Himalayan Mountains,' in 

 two volumes quarto, with 100 plates. This is the only book 

 except Dr. Wallich's 'Tentamen Florae Nepalensis,' devoted 

 to the rich flora of these mountains ; and it further contains 

 the first and only attempt to demonstrate the prominent fea- 

 tures of the geographical distribution of Northern Indian 

 plants in reference to the elevations and climates they inhabit, 

 and to the botany of surrounding countries. A vast amount 

 of valuable miscellaneous botanical matter is here brought 

 together, with characters of a considerable number of species. 

 These, however, are rather to be regarded as indications of 

 the sujiposed novelties in the author's herbarium, than as de- 

 scriptions available for botanical purposes. This should be 



