78 



TRANSACTIONS AND PROCEEDINGS OF TlIK [Sess. lxv. 

 Taiuj: n'. 



12th 



December 



to 12th 



January. 



During the period ending 12th January 1888, rain fell 

 on ten days between loth and 31st of December, 4"15 

 inches; and 0-93 inch fell on 6th, 7th, and 8th of January. 

 The rainfall being, for San Jorge, decidedly fiequent, it is 

 possible that the sun had not as much opportunity as usual 

 to warm the earth sufficiently to produce hot nights ; and 

 thus the contrast between a sun-heated earth and a rain- 

 cooled earth is wanting. 



Looking now at 1889, the same solution offers itself as 

 in the case of 1888 ; for the Meteorological Eecords show 

 that during this 12th January period, from 12th to 31st 

 December, rain fell 2 '4 6 inches on eight days out of the 

 twenty, and 2'72 inches on six days out of the eleven from 

 1st to 11th January; never more than two consecutive 

 days without rain, except from 2oth to 29th December. 



The slight over-average growth of the period ending 

 12th January 1891 is doubtless due to a fall on 10th and 

 11th December 1890, which would of course take effect 

 after the measurement of trees on 12th December. 



Thus in these seven periods, reasons that seem to be 

 good are offered to account for a rather over-average 

 minimum temperature accompanying an over-average 

 growth of deciduous trees during the growing season. 



It almost seems as if it were proved that rain is the 

 only one of the weather-factors here taken into considera- 

 tion that has any actual effect on the growth of trees ; a 

 low maximum thermometer in summer is due to rain ; a 

 high minimum thermometer (in the case of evergreens) in 

 winter is due to rain ; absence of sunshine is due to rain 

 and clouds ; all are attendant on good growth, but all are 

 due to rain. 



