DERIVATION OF THE FLORA OF HAWAII 11 



viving the heat and dryness of the lowlands, and their spores are not fit- 

 ted for long- periods of desiccation. 



In the rain forest occur also a number of filmy ferns (Hymenophyl- 

 laceae), plants of extreme delicacy, which could hardly have reached the 

 islands by any conceivable form of transport. 



In view of these facts, the writer decided to visit the islands with 

 the special purpose of collecting liverworts, to see to what extent they 

 confirmed Pilsbry's conclusions derived from his study of the land mol- 

 luscs. The results were strongly confirmatory, and it seemed worth 

 while to look into the relationships of the higher plants, which brought 

 out to a surprising degree the close connection of the flora, as a whole, 

 with the Southern Pacific regions, especially Australasia and Indo- 

 Malaysia. 



In a previous paper 8 the principal results of these studies have been 

 recorded ; and in the present paper it is proposed to extend these studies 

 and to present the data derived from the animal life as well. 



The algae and fungi are as yet too imperfectly known to make an 

 entirely satisfactory comparison with those of other regions. A recent 

 list of the algae published by Professor McCaughey 9 contains a good 

 many cosmopolitan species, as well as a considerable number of endemic 

 ones. Of the non-endemic, but not cosmopolitan, species, the majority 

 appear to be related to those of the South Pacific and Indian Oceans, but 

 the data are too incomplete to make it safe to assume this without reserve. 



BRYOPHYTES 



The writer has not been able to secure satisfactory data as to the 

 mosses of Hawaii, but the liverworts have received considerable atten- 

 tion from collectors, and the writer has devoted some time to collecting 

 and studying these plants. Hepaticae are very abundant in the rain for- 

 est, especially at higher elevations, 3,000 to 5,000 feet. The liverworts 

 are presumably ancient types, as is attested by their present distribution. 

 The lower forms are delicate thallose plants of very simple structure. 

 These are relatively few in number when compared to the leafy types 

 "scale mosses," as they are sometimes called. The latter are evidently 

 more specialized, and presumably more modern types than the thallose 

 species. 



The writer made collections of liverworts from several localities in 



8 Campbell, D. H.: "The Origin of the Hawaiian Flora," Memoirs of the 

 Torrey Botanical Club, 17, 90-96. 1918. 



9 McCaughey, V. : "Algae of the Hawaiian Archipelago," Bot. Gaz., 65, 42-57 ; 

 121-149. 1918. 



