144 NOTES OF A NATURALIST. 



Such seasons appear to recur six or seven times in 

 each century, and it is clear that, according as the 

 meteorologist happens to include or exclude such a 

 season in his data, the figures expressing the average 

 must vary very largely. Inasmuch as plant life is 

 regulated by the ordinary conditions of temperature 

 and moisture, we are less liable to error in taking the 

 results which exclude exceptional seasons. 



In discussing, therefore, the conditions of vegetation 

 in Central Chili, it seems safe to conclude that the 

 averages given in the following table, extracted from 

 the careful work of Julius Hann, '' Lehrbuch der 

 Klimatologie," are above rather than below the ordi- 

 nary limit. I find, indeed, that while the average rain- 

 fall at Santiago during the twelve years from 1849 

 to i860 was 419 millimetres, or nearly 16 J English 

 inches, the average for the six years from 1866 to 

 1 87 1 was 299 millimetres, or less than 12 inches. It 

 is evident that the indigenous vegetation must be 

 adapted to thrive upon the smaller amount of moisture 

 expressed by the latter figures. 



The following table, compiled from Hann's work, 

 gives the most reliable results now available, and 

 shows the mean temperature of the year, of the 

 hottest and coldest months, the extremes of annual 

 temperature, and the rainfall for the chief places in 

 Chili, with a few blanks where information is not 

 available. The maxima and minima do not express 

 the absolute extremes attained during the entire period 

 for which observations are available, but the means of 



Historico sobrc el Clima de Chile" (Valparaiso : 1877), from which I 

 have borrowed the above-mentioned particulars. 



