THE PROBLEMS OF ANTARCTIC PLANT LIFE. 5 



abundant in the south, and winter temperatures, at least in the outermost south 

 polar regions, neglecting for the moment comparative latitudes, are not more severe 

 than iu the north. 



The real explanation is probably to be found in the short and inadequate Antarctic 

 summer, with its remarkably low temperatures. Thus, for example, at the South 

 Orkneys, in 60 44' S., the mean of the summer months (December, January, and 

 February) is barely 32 F., and in no mouth does the mean rise to 33 F., while the 

 mean of the warmest day in 1903-04 was only 377 F. ; at Snow Hill Island, Louis 

 Philippe Land (64 24' S.), the mean of the warmest month (January) was found to 

 be only 30'38 F., while at Cape Adare, Victoria Land, in 71 18' S., the summer 

 mean is 30 '4 F. 



At 77 50' S., 166 44' E., in McMurdo Sound, the Discovery found that the mean 

 summer temperature was 21 '4 F., and the mean of the warmest month, December, 

 was 24-6 F. 



These temperatures may be compared with those of the Arctic regions. Thus at 

 Spitsbergen (79 53' N.) the mean temperature of July (the corresponding month to 

 January in the south) is as high as 4T5 F., while in Franz Josef Land, in over 80 N., 

 it is not lower than 35 '6 F. iu the same month. The mean of the Spitsbergen summer 

 (June, July, and August) is 37'1, contrasted with the corresponding mean given above 

 for the South Orkneys, scarcely 32 F. Examples could thus be multiplied, but all 

 would bring out the same important point that while the Arctic summer mean is well 

 above 32 F., the Antarctic summer mean is practically always below. This remarkably 

 cold Antarctic summer acts in two ways upon plant life : firstly, the winter snow lies 

 late on the ground all the later as the summer is a cloudy and somewhat sunless 

 period, and December is well advanced before the majority of available sites are laid 

 bare, while iu February the winter again begins 1 ; secondly, and this is the chief reason, 

 it is doubtful if a flowering plant could obtain the requisite amount of heat needed for 

 its various life functions even to reach the flowering stage, while the maturation of its 

 fruit would be next to impossible. In fact, one could with much truth say that the 

 Antarctic summer is but an astronomical conception : those who have experienced it 

 know well how little reality it has. Doubtless, then, in this want of a season of 

 growth lies a quite adequate explanation of the poverty of the south polar vegetation, 

 but I think that there is also another adverse influence at work. Even supposing that 

 a species did obtain a footing on Antarctica, as is not impossible in the lands nearest 

 Fuegia, considering the narrowness of Drake Strait, its continued existence would be at 

 once menaced by the presence of the myriads of penguins which occupy almost every 

 bare spot of ground during the nesting and breeding season. There is no parallel in 

 the north to these penguins and the power they would have in destroying any vegetable 



1 Contrast this with the north, where, for example, at the northern part of the east coast of Greenland, the land 

 is clear of snow from May or early June until September, dates which would correspond in the south to 

 November to March. 



