1915] SMILEY—LAKE TAHOE REGION 273 
of the alpine climate: the displacing of the heat total toward the 
end of summer and fall. The start of the vegetative period (the 
local ‘“‘spring”’) is delayed till summer is well advanced below, but 
the brilliant insolation of the alpine day in part compensates for 
this late beginning, so that ‘fall’? phenomena are nearly contem- 
poraneous both above and below. ‘‘ Die Primeln bliihen auf dem 
Rigi bei 1800 m. ca. 6 Wochen spiter als in Ziirich, die Herbst- 
zeitlose dagegen beinahe gleichzeitig’”’ (6). 
Fic ike and Arctic-alpine zones: Desolation Valley at Lake LeConte 
and Pyeeuita Pea 
It has been stated that the zone of maximum rainfall in the 
Sierra is between sooo and 7000 feet: Colfax (2421 feet), 46.64 
in. per year; Cisco (5939 feet), 49.68 in. per year; Summit (7017 
feet), 46.58 in. per year (mean of 30 years); but the diminished 
rainfall at Summit may be due to the influence of the arid east, an 
influence not barred by high ranges. A comparison of the same 
period (1909-13) shows at Summit (7017 feet) 40.98 in. mean 
total precipitation, and at Tamarack (8000 feet) 52.77 in. It will 
be noted that this would seem to have been a period of less than 
normal rainfall, the deviation amounting to 12.3 per cent. If 
such was the case, the precipitation at Tamarack should normally 
