THK PROBLEMS OF ANTARCTIC PLANT I. IKK. 11 



the /''< I/MI Pftaf speaks 1 of the almost continuous carpets of Usnta at 

 M Island. 



Two other species, fthitocarpongeographicum, D.C., and Lccideafu*co-atra, Tli. I 

 are less al>un<l:iiit. an. I owing to their more sombre colour and less striking appear- 

 ;iin < il<> not, as a nil.-, lend any very characteristic feature to the landscape. The numlter 

 ..f Antan -lit- ln-li.-ns so far known is 88, but the reports on several ivri-nt collections 

 - yet to be published. Future exploration will certainly add greatly to this numlwr. 

 species were found by tin- Scotia at the South Orkneys, and with regard to these 

 Dr 0. V. Darbish ire reports* that all except one were previously recorded from some 

 part of the Arctic regions, and that, taking into account all known collections, the pro- 

 portion of Arctic species is as high as 73 to 75 per cent. Of the Discovery collections 

 76 per cent, were also Arctic in distribution. The lichens of Gerlache Strait as collected 

 by the Bflgica numbered 55, including a new species of Placodium (P. regale, Wainio), 

 which was also found by me at the South Orkneys and independently described as 

 P. Jrttticulosum, Darbish.: Wainio's name, however, has priority. Of these 55 species 

 38*2 percent were known from Arctic regions, and as many as 527 per cent, were new. 

 All the 3 species recorded from Wilhelm Land are of wide distribution. Since these 

 statistics include in each case many cosmopolitan or very widely spread species, which 

 are common among lichens, it would be unwise to base on them arguments concerning 

 the origin of the Antarctic flora. 



The multicellular algae of Antarctic seas are quite abundant as regards individuals, 

 if perhaps the species are not very numerous. Fifteen species are recorded by Mr and 

 Mrs Gepp from my South Orkney collections, and Mr Holmes records 9 other species 

 in a small collection made by the expedition in the same place. Of the species deter- 

 mined by Mr and Mrs Gepp, 5 are new. I am confident that careful exploration of 

 the coasts of these islands at seasons when they are free from ice would reveal many 

 more species. As was only to be expected, the littoral region, i.e. the area between 

 high and low water, proved poor both in individuals and species ; calcareous species are 

 the most abundant in that region. The wearing and tearing action of the ice is not 

 compatible with much algal growth in these shallow waters, and this no doubt accounts 

 for the absence of the southern kelp (Macrocystis pyrifera) from the true Antarctic 

 regions. The majority of the algae occur at greater depths. The daily haul of the 

 dredge which we took in Scotia Bay scarcely ever failed to bring up specimens of algae. 

 The two red algas (Plocamium coccineum, Lyngb., and Acanthococcut spinuliyer, Hook, 

 and Harv.) were extraordinarily abundant in 10 fathoms, and the brown alga (Uesma- 

 restia Rossii, Hook, and Harv.) was frequent in shallower water. Calcareous alga- 

 were obtained almost daily in 9 to 1 fathoms. In places these algae cover the rocks 

 in a few feet of water with so continuous an incrustation that at first sight one is 

 deceived into the belief that it is an ice formation. Probably the most interesting find 



1 Rmfportt fraiminmirm nur la tr-iranx ezfruU* dtau rmterrfiftt, Acadrmie dea Sciences PrU, 1 1, P- 

 * Sec this volume, pp. **-, and " The BoUny of the Sooth Orkneys : Lichens," O. V. Darbiihire (lac. ctf.). 



