[ADAMS] CLIMATIC FACTORS IN RELATION TO PLANT LIFE 107 
CLIMATIC FACTORS. 
In the present discussion only the more prominent factors are 
taken into consideration although probably every slight variation 
of any one of the numerous constituents of a climate affects to some 
extent the vegetation of the locality in question. For example, 
barometric pressure, relative humidity, and cloudiness are not dealt 
with partly for the reason that it is difficult to give a general and 
concise summary of each for the year or half year. Barometric 
pressure considered by itself seems to have little effect on plants except 
possibly those growing at high altitudes. The indirect consequences, 
however, in the form of rain and wind are of great importance. The 
effects of relative humidity and cloudiness are probably better ex- 
pressed under evaporation and sunshine. 
An enumeration of the climatic elements considered by Schimper 
to be of most importance in relation to plants will be found in his 
“Plant Geography”’ English Edition, 1903. 
The factors here considered may be grouped under five heads, 
namely, Temperature, Light, Precipitation, Evaporation, and Wind. 
In dealing with the climate of any particular place the latitude, longi- 
tude and altitude above the sea-level should always be given. The 
latitude, etc., of the places mentioned in this paper are as follows:— 
