INTKODUCTIOX TO THE EEPOKTS ON INSULAE FLOEAS. 9 



Taking all the plants, both native and introduced, we have as the proportion of species to each 

 genus, ............... 2 - 58 



To endemic genera alone, ............. 3"94 



To genera represented only by endemic species, ......... 1 '28 



To introduced genera, ......... .... 1 '07 



Endemic genera of only one species, ...... .... 16 



Genera of a single endemic species, ........... 49 



Introduced genera of one species,' ...... .... 43 



Other genera of one species, ............ 45 



Percentage of all the endemic species, . . . . . . . . . 68*05 



,, ,, species of endemic genera, . . . . . . . . . 2S'0 



„ ,, introduced species, . . . . . . . . . . .12-46 



The grasses were left undetermined by Mann, and are not included in the foregoing 

 figures. About twenty-two species have been recorded, four of which are endemic. 



Since the publication of Mann's Enumeration of Hawaiian Plants and the foregoing 

 analysis of it, Dr H. Wawra, who spent four months in the islands during the cruise of the 

 Austrian frigate " Donau," and formed very extensive botanical collections, has made two 

 important contributions to our knowledge of their vegetation, in the Flora for 1872-75, 

 and the (Esterreichische Botanische Zeitung for 1872 and 1873. Judging from a 

 superficial examination, the latter is by far the most complete account of the aspects 

 of the vegetation of the Sandwich Islands in existence ; and the former not only contains 

 descriptions of between forty and fifty new species of flowering plants, besides a large 

 number of varieties, but it likewise includes full descriptions of many previously imper- 

 fectly known plants. It is singular with this very considerable accession of species there 

 is nothing generically new, for Wawra does not appear to have established critical species. 

 Dr Engler (Versuch einer Eutwicklungsgeschichte der Pflanzenwelt, ii. pp. 104-145), has 

 fully tabulated the distribution of all the Sandwich Islands vascular plants with reference 

 to their nearest allies ; and he finds that 500, or 74"6 per cent, of the 6G9 species which he 

 regards as indigenous, are endemic. The vascular cryptogams number 140, whereof 57 

 are endemic, thus leaving 529 flowering plants, 443 of which are endemic. 



A further addition has been made to the number of endemic species in the Sandwich 

 Islands flora in Mr C. B. Clarke's monograph of the Cyrtandrese, 1 a group of plants widely 

 spread in Polynesia, from which we extract the following particulars of the distribution of 

 this tribe and of the genus Cyrtandra, the only one represented in this group. 



The Gesnerese are restricted to America, while the Cyrtandrese are almost confined to 

 the Old World ; the great body of the tribe being situated in South-east Asia, extending 

 from India to Japan and New Guinea ; a single genus, Cyrtandra, having numerous 

 species scattered through Polynesia to Tahiti and the Sandwich Isles. The Cyrtandreae 

 may be conceived as nearly continuous over this area, abounding both in variety of forms 

 and number of individuals. External to this area we find only a few small groups, 



1 In De Candolle's Suites au Prodromus Systematis Naturalis Eegni Vegetabilis, vol. v. par. 1. 



