150 



DISCOVERY 



In spite of careful search in other parts of Antarctic 

 regions, these plants have not been found elsewhere, 

 although there is a possibility of their occurrence 

 in the South Orkneys. They grow sparingly in 

 scattered groups and give the impression of being 

 almost at the limit of possible existence. Reproduc- 

 tion would appear to be entirely vegetative. 



Ferns are entirely lacking in the Antarctic, but 

 mosses are numerous and, in fact, are one of the chief 

 constituents of the flora, in individuals if not in 

 species. Well over fifty species are now described 

 from Antarctic regions, of which the majority come 

 from the Graham Land region and neighbouring 

 islands. Man}' specimens show a vigorous, even 

 luxuriant, growth, and this is specially notable in 

 certain species that have a wide distribution throughout 

 high latitudes. The specimens from Victoria Land in 

 lat. 78° S. are stunted and miserable compared with 

 those from Graham Land fifteen degrees farther north. 

 In the far south they are frozen solid, as hard as rock, 

 for some ten or eleven months, in Graham Land and 

 the South Orkneys for seven or eight months, but this 

 experience does not seem to impair their vitality. 

 The mosses generally grow in small colonies, in favoured 

 places, in which a number of species are to be found. 

 In some cases a small tundra of moss and lichen 

 vegetation half an acre in extent may be found. Such 

 places are favourite nesting-places of skuas and gulls ; 

 the bird guano provides a valuable fertiliser to the 

 moss. Most Antarctic mosses reproduce vegetatively ' : 

 fruiting specimens are rare. Dr. J. Cardot, the great 

 authority on Antarctic mosses, says that among all 

 the specimens he has examined only six species showed 

 fruits. Even among the specimens from the South 

 Orkneys, where moss growth is luxuriant, only one 

 species showed many well-developed fruits 



Antarctic hepatics or liverworts are rare. The half- 

 dozen or so of species seem all to have been recorded 

 from the Graham Land region. The\' are generally 

 found growing in the shelter of moss colonies. Lichens 

 are numerous, and both as species and individuals 

 form the predominant feature of Antarctic plant life, 

 marine algte excepted. Even in mid-winter a few 

 precipitous rock faces may show a touch of colour 

 due to lichen growth, while in summer there are great 

 patches of brilliant orange, due mainly to various 

 species of Placodium, and shaggy growth of a luxuriant 

 species of Usnea. There are few, if any, areas of bare 

 rock in summer which do not support some lichen 

 growth. Dr. 0. V. Darbishire has recorded over 

 100 species of lichens in Antarctic regions. Subsequent 

 exploration will certainly add to this number. 



' Vegetative reproduction is shown by plants which, hke the 

 begonia, can multiply without the production of seeds. 



Red Snow 



Fresh-water algje are comparatively abundant. In tlii-' 

 South Orkneys alone sixty-eight species were recorded. 

 The forms of most interest are those that give origin 

 to red and }-ellow snow. Red snow is not very common, 

 but has been recorded from various parts of Antarctic 

 and Arctic regions, as well as from extra-polar regions. 

 Dr. Fritsch, on examining South Orkney material 

 collected from a patch of red snow, found it to be due 

 to an algal association ; but in Victoria Land Mr. J. 

 Murray attributed the colour not to algal growth, but 

 to the presence of red rotifers. These have been found 

 in red snow in the Alps, but, as far as I am aware, 

 not in Arctic regions. Yellow snow is rare. At tlir 

 South Orkneys it is due to a remarkable association of 

 eighteen species of algje and two of fungi, with a 

 character so reminiscent of plankton'^ that it may be du. 

 to wind carriage of plankton forms on to the land. This 

 must not be confused with the yellow coloration of 

 sea-ice which is due to included diatoms. In yellow 

 snow diatoms are rare. 



Marme alg;E are very abundant in Antarctic seas. 

 As in Arctic waters, the rock pools and shore-line 

 generally are comparatively free from seaweeds owing 

 to the scouring action of the ice. This gives a false 

 impression of the poverty of marine life. In wato 

 over 10 or 15 feet in depth there are many seaweeds ; 

 in shallow water onlj- calcareous algae encrusted on 

 the rocks are at all conspicuous. 



Unicellular marine algae occur in enormous numbers. 

 Sir J. Hooker was the first to demonstrate this pheno- 

 menon, and since his day every expedition has corro- 

 borated his statement, though comparatively few 

 have made exhaustive collections. South of lat. 60° S. 

 the plankton changes its character : animal forms 

 become scarce and plant forms predominate. In the 

 regions of pack-ice diatoms and a few peridinians con- 

 stitute the surface life of the sea. A few minutes' 

 haul of a fine silk net results in half a pint to a pint 

 of gelatinous matter which is almost wholly composed 

 of diatoms. Some ten or twelve species are very 

 common, and some forty to fifty are rarer. The Arctic 

 seas show the same abundance of diatoms, sometimes 

 to such an extent that the sea appears bright green 

 for several acres. This discoloration of the sea has 

 seldom been recorded in the Antarctic. It is of 

 interest to note that Dr. L. Mangin finds on comparison 

 that the Arctic and Antarctic diatom floras are 

 practically distinct as regards species, and that there 

 is also much difference in various parts of Antarctic 

 seas. 



^ " Plankton " is a general name given to those minute forms 

 of sea life which exist either on or just below the surface of 

 the ocean. 



