Till. ri:>lil I M- i >F ANTAKCTIC PLANT I. Ill 5 



almnd.int in tin- >outh. and winter temp, ratines, at least in the outermost south 

 polar nonius, ne^leeting for the moment comparative latitudes, are not more m 

 than in the nitrth. 



Tin- real explanation is pr<>liul>ly to be found in the short and inadequate Antarctic 

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

 Orkneys, in 60 44' S., the mean <>f the summer months (I>eeeml>er, January, and 

 February) is liarely -'J- F., and in no month does the mean rise to 33 F., while the 

 ni--aii of the warmest day in 1903-04 was only 377 K. ; at Snow Hill Island, Louis 

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

 be only 30'38 e R, 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 MoMurdo Sound, the Discovei-y found that the mean 

 summer temperature was 2P4 F., and the mean of the warmest month, December, 

 , 1 1 .; r. 



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

 Spit.-liergen (79 53' N.) the mean temperature of July (the corresponding month to 

 January in the south) is as high as 41 '5 F., while in Franz Josef Land, in over 80 N., 

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

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

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

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

 above 32" F., the Antarctic summer mean is practically always lielow. 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 m 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 ev. \\ 

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

 the north t-i these penguins and the power they would have in destroying any vegetable 



1 Contrast thU with tin- north, where, for example, at the northern part of the east court, of Greenland, the land 

 is clear of now from May or early June until September, date* which would corroipond in the tooth to 

 ; nber to March. 



